AMERICAN MATHEMATICS COMPETITION - 2001

PROBLEM 1 :

Casey's shop class is making a golf trophy. He has to paint 300 dimples on a golf ball. If it takes him 2 seconds to paint one dimple, how many minutes will he need to do his job?

(A) 4
(B) 6
(C) 8
(D) 10
(E) 12

ANSWER : (D) 10


PROBLEM 2 :

I'm thinking of two whole numbers. Their product is 24 and their sum is 11 . What is the larger number?
(A) 3
(B) 4
(C) 6
(D) 8
(E) 12

ANSWER : (D) 8

PROBLEM 3 :

Granny Smith has $\$ 63$. Elberta has $\$ 2$ more than Anjou and Anjou has onethird as much as Granny Smith. How many dollars does Elberta have?
(A) 17
(B) 18
(C) 19
(D) 21
(E) 23

ANSWER : (E) 23

PROBLEM 4 :

The digits $1,2,3,4$ and 9 are each used once to form the smallest possible even five-digit number. The digit in the tens place is
(A) 1
(B) 2
(C) 3
(D) 4
(E) 9

ANSWER : (E) 9

PROBLEM 5 :

On a dark and stormy night Snoopy suddenly saw a flash of lightning. Ten seconds later he heard the sound of thunder. The speed of sound is 1088 feet per second and one mile is 5280 feet. Estimate, to the nearest half-mile, how far Snoopy was from the flash of lightning.
(A) 1
(B) $1 \frac{1}{2}$
(C) 2
(D) $2 \frac{1}{2}$
(E) 3

ANSWER : (C) 2

PROBLEM 6 :

Six trees are equally spaced along one side of a straight road. The distance from the first tree to the fourth is 60 feet. What is the distance in feet between the first and last trees?
(A) 90
(B) 100
(C) 105
(D) 120
(E) 140

ANSWER : (B) 100

Problems 7, 8 and 9 are about these kites.

PROBLEM 7 :

To promote her school's annual Kite Olympics, Genevieve makes a small kite and a large kite for a bulletin board display. The kites look like the one in the diagram. For her small kite Genevieve draws the kite on a one-inch grid. For the large kite she triples both the height and width of the entire grid.
What is the number of square inches in the area of the small kite?
(A) 21
(B) 22
(C) 23
(D) 24
(E) 25

ANSWER : (A) 21

PROBLEM 8 :

Genevieve puts bracing on her large kite in the form of a cross connecting opposite corners of the kite. How many inches of bracing material does she need?
(A) 30
(B) 32
(C) 35
(D) 38
(E) 39

ANSWER : (E) 39

PROBLEM 9 :

The large kite is covered with gold foil. The foil is cut from a rectangular piece that just covers the entire grid. How many square inches of waste material are cut off from the four corners?
(A) 63
(B) 72
(C) 180
(D) 189
(E) 264

ANSWER : (D) 189

PROBLEM 10 :

A collector offers to buy state quarters for $2000 \%$ of their face value. At that rate how much will Bryden get for his four state quarters?
(A) 20 dollars
(B) 50 dollars
(C) 200 dollars
(D) 500 dollars
(E) 2000 dollars

ANSWER : (A) 20 dollars


PROBLEM 11 :

Points $A, B, C$ and $D$ have these coordinates: $A(3,2), B(3,-2), C(-3,-2)$ and $D(-3,0)$. The area of quadrilateral $A B C D$ is

(A) 12
(B) 15
(C) 18
(D) 21
(E) 24


ANSWER : (C) 18

PROBLEM 12 :

If $a \otimes b=\frac{a+b}{a-b}$, then $(6 \otimes 4) \otimes 3==$
(A) 4
(B) 13
(C) 15
(D) 30
(E) 72


ANSWER : (A) 4

PROBLEM 13 :

Of the 36 students in Richelle's class, 12 prefer chocolate pie, 8 prefer apple, and 6 prefer blueberry. Half of the remaining students prefer cherry pie and half prefer lemon. For Richelle's pie graph showing this data, how many degrees should she use for cherry pie?
(A) 10
(B) 20
(C) 30
(D) 50
(E) 72

ANSWER : (D) 50


PROBLEM 14 :

Tyler has entered a buffet line in which he chooses one kind of meat, two different vegetables and one dessert. If the order of food items is not important, how many different meals might he choose?

ANSWER : (C) 72

PROBLEM 15 :

Homer began peeling a pile of 44 potatoes at the rate of 3 potatoes per minute. Four minutes later Christen joined him and peeled at the rate of 5 potatoes per minute. When they finished, how many potatoes had Christen peeled?
(A) 20
(B) 24
(C) 32
(D) 33
(E) 40

ANSWER : (A) 20


PROBLEM 16 :

A square piece of paper, 4 inches on a side, is folded in half vertically. Both layers are then cut in half parallel to the fold. Three new rectangles are formed, a large one and two small ones. What is the ratio of the perimeter of one of the small rectangles to the perimeter of the large rectangle?

(A) $\frac{1}{3}$
(B) $\frac{1}{2}$
(C) $\frac{3}{4}$
(D) $\frac{4}{5}$
(E) $\frac{5}{6}$

ANSWER : (E) $\frac{5}{6}$

PROBLEM 17 :

For the game show Who Wants To Be A Millionaire?, the dollar values of each question are shown in the following table (where $\mathrm{K}=1000$ ).

Between which two questions is the percent increase of the value the smallest?
(A) From 1 to 2v
(B) From 2 to 3
(C) From 3 to 4
(D) From 11 to 12
(E) From 14 to 15

ANSWER : (B) From 2 to 3

PROBLEM 18 :

Two dice are thrown. What is the probability that the product of the two numbers is a multiple of 5 ?
(A) $\frac{1}{36}$
(B) $\frac{1}{18}$
(C) $\frac{1}{6}$
(D) $\frac{11}{36}$
(E) $\frac{1}{3}$

ANSWER : (D) $\frac{11}{36}$

PROBLEM 19 :

Car M traveled at a constant speed for a given time. This is shown by the dashed line. Car N traveled at twice the speed for the same distance. If Car N's speed and time are shown as solid line, which graph illustrates this?

ANSWER : (D)

PROBLEM 20 :

Kaleana shows her test score to Quay, Marty and Shana, but the others keep theirs hidden. Quay thinks, "At least two of us have the same score." Marty thinks, "I didn't get the lowest score." Shana thinks, "I didn't get the highest score." List the scores from lowest to highest for Marty (M), Quay (Q) and Shana (S).
(A) $S, Q, M$
(B) Q,M,S
(C) Q,S,M
(D) $M, S, Q$
(E) $S, M, Q$

ANSWER : (A) $S, Q, M$

PROBLEM 21 :

The mean of a set of five different positive integers is 15 . The median is 18 . The maximum possible value of the largest of these five integers is
(A) 19
(B) 24
(C) 32
(D) 35
(E) 40

ANSWER : (D) 35

PROBLEM 22 :

On a twenty-question test, each correct answer is worth 5 points, each unanswered question is worth 1 point and each incorrect answer is worth 0 points. Which of the following scores is NOT possible?
(A) 90
(B) 91
(C) 92
(D) 95
(E) 97

ANSWER : (E) 97

PROBLEM 23 :


Points $R, S$ and $T$ are vertices of an equilateral triangle, and points $X, Y$ and $Z$ are midpoints of its sides. How many noncongruent triangles can be drawn using any three of these six points as vertices?



(A) 1
(B) 2
(C) 3
(D) 4
(E) 20

ANSWER : (D) 4


PROBLEM 24 :

Each half of this figure is composed of 3 red triangles, 5 blue triangles and 8 white triangles. When the upper half is folded down over the centerline, 2 pairs of red triangles coincide, as do 3 pairs of blue triangles. There are 2 red-white pairs. How many white pairs coincide?


(A) 4
(B) 5
(C) 6
(D) 7
(E) 9

ANSWER : (B) 5


PROBLEM 25 :

There are 24 four-digit whole numbers that use each of the four digits 2,4 , 5 and 7 exactly once. Only one of these four-digit numbers is a multiple of another one. Which of the following is it?
(A) 5724
(B) 7245
(C) 7254

(D) 7425

(E) 7542

ANSWER : (D) 7425

American Mathematics Competition - 2012

Problem 1

Rachelle uses 3 pounds of meat to make 8 hamburgers for her family. How many pounds of meat does she need to make 24 hamburgers for a neighborhood picnic?

Answer:

(E) 9.

Problem 2


In the country of East Westmore, statisticians estimate there is a baby born every 8 hours and a death every day. To the nearest hundred, how many people are added to the population of East Westmore each year?


(A) 600
(B) 700
(C) 800
(D) 900
(E) 1000

Answer:

(B) 700.

Problem 3


On February 13 The Oshkosh Northwester listed the length of daylight as 10 hours and 24 minutes, the sunrise as 6:57 am, and the sunset as 8:15 pm. The length of daylight and sunrise were correct, but the sunset was wrong. When did the sun really set?
(A) 5:10 PM
(B) 5:21 PM
(C) 5:41 PM
(D) 5: 57 PM
(E) 6:03 PM

Answer:

(B) 5:21 PM.

Problem 4


Peter's family ordered a 12 -slice pizza for dinner. Peter ate one slice and shared another slice equally with his brother Paul. What fraction of the pizza did Peter eat?


(A) $\frac{1}{24}$
(B) $\frac{1}{12}$
(C) $\frac{1}{8}$
(D) $\frac{1}{6}$
(E) $\frac{1}{4}$

Answer:

(C) $\frac{1}{8}$

Problem 5


In the diagram, all angles are right angles and the lengths of the sides are given in centimeters. Note the diagram is not drawn to scale. What is X, in centimeters?


(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

Answer:

(E) 5.

Problem 6


A rectangular photograph is placed in a frame that forms a border two inches wide on all sides of the photograph. The photograph measures 8 inches high and 10 inches wide. What is the area of the border, in square inches?


(A) 36
(B) 40
(C) 64
(D) 72
(E) 88

Answer:

(E) 88.

Problem 7


Isabella must take four 100 -point tests in her math class. Her goal is to achieve an average grade of at least 95 on the tests. Her first two test scores were 97 and 91. After seeing her score on the third test, she realized that she could still reach her goal. What is the lowest possible score she could have made on the third test?


(A) 90
(B) 92
(C) 95
(D) 96
(E) 97

Answer:

(B) 92.

Problem 8

A shop advertises that everything is "half price in today's sale." In addition, a coupon gives a $20 \%$ discount on sale prices. Using the coupon, the price today represents what percentage discount off the original price?


(A) 10
(B) 33
(C) 40
(D) 60
(E) 70

Answer:

(D) 60.

Problem 9


The Fort Worth Zoo has a number of two-legged birds and a number of fourlegged mammals. On one visit to the zoo, Margie counted 200 heads and 522 legs. How many of the animals that Margie counted were two-legged birds?


(A) 61
(B) 122
(C) 139
(D) 150
(E) 161

Answer:

(C) 139.

Problem 10


How many 4 -digit numbers greater than 1000 are there that use the four digits of 2012?


(A) 6
(B) 7
(C) 8
(D) 9
(E) 12

Answer:

(D) 9.

Problem 11


The mean, median, and unique mode of the positive integers $3,4,5,6,6,7, x$ are all equal. What is the value of $x$ ?
(A) 5
(B) 6
(C) 7
(D) 11
(E) 12

Answer:

(D) 11.

Problem 12


What is the units digit of $13^{2012}$ ?
(A) 1
(B) 3
(C) 5
(D) 7
(E) 9

Answer:

(A) 1.

Problem 13


Jamar bought some pencils costing more than a penny each at the school bookstore and paid $\$ 1.43$. Sharona bought some of the same pencils and paid $\$ 1.87$. How many more pencils did Sharona buy than Jamar?


(A) 2
(B) 3
(C) 4
(D) 5
(E) 6

Answer:

(C) 4.

Problem 14


In the BIG N, a middle school football conference, each team plays every other team exactly once. If a total of 21 conference games were played during the 2012 season, how many teams were members of the BIG N conference?
(A) 6
(B) 7
(C) 8
(D) 9
(E) 10

Answer:

(B) 7.

Problem 15


The smallest number greater than 2 that leaves a remainder of 2 when divided by $3,4,5$, or 6 lies between what numbers?


(A) 40 and 50
(B) 51 and 55
(C) 56 and 60
(D) 61 and 65
(E) 66 and 99

Answer:

(D) 61 and 65.

Problem 16


Each of the digits $0,1,2,3,4,5,6,7,8$, and 9 is used only once to make two five-digit numbers so that they have the largest possible sum. Which of the following could be one of the numbers?


(A) 76531
(B) 86724
(C) 87431
(D) 96240
(E) 97403

Answer:

(C) 87431.

Problem 17


A square with an integer side length is cut into 10 squares, all of which have integer side length and at least 8 of which have area 1 . What is the smallest possible value of the length of the side of the original square?


(A) 3
(B) 4
(C) 5
(D) 6
(E) 7

Answer:

(B) 4.

Problem 18


What is the smallest positive integer that is neither prime nor square and that has no prime factor less than 50 ?


(A) 3127
(B) 3133
(C) 3137
(D) 3139
(E) 3149

Answer:

(A) 3127.

Problem 19


In a jar of red, green, and blue marbles, all but 6 are red marbles, all but 8 are green, and all but 4 are blue. How many marbles are in the jar?


(A) 6
(B) 8
(C) 9
(D) 10
(E) 18

Answer:

(C) 9.

Problem 20


What is the correct ordering of the three numbers $\frac{5}{19}, \frac{7}{21}$, and $\frac{9}{23}$, in increasing order?


(A) $\frac{9}{23}<\frac{7}{21}<\frac{5}{19}$
(B) $\frac{5}{19}<\frac{7}{21}<\frac{9}{23}$
(C) $\frac{9}{23}<\frac{5}{19}<\frac{7}{21}$
(D) $\frac{5}{19}<\frac{9}{23}<\frac{7}{21}$
(E) $\frac{7}{21}<\frac{5}{19}<\frac{9}{23}$

Answer:

(B) $\frac{5}{19}<\frac{7}{21}<\frac{9}{23}$

Problem 21


Marla has a large white cube that has an edge of 10 feet. She also has enough green paint to cover 300 square feet. Marla uses all the paint to create a white square centered on each face, surrounded by a green border. What is the area of one of the white squares, in square feet?


(A) $5 \sqrt{2}$
(B) 10
(C) $10 \sqrt{2}$
(D) 50
(E) $50 \sqrt{2}$

Answer:

(D) 50.

Problem 22


Let $R$ be a set of nine distinct integers. Six of the elements of the set are 2, 3, 4, 6,9 , and 14 . What is the number of possible values of the median of $R$ ?


(A) 4
(B) 5
(C) 6
(D) 7
(E) 8

Answer:

(D) 7.

Problem 23


An equilateral triangle and a regular hexagon have equal perimeters. If the area of the triangle is 4 , what is the area of the hexagon?
(A) 4
(B) 5
(C) 6
(D) $4 \sqrt{3}$
(E) $6 \sqrt{3}$

Answer:

(C) 6.

Problem 24
A circle of radius 2 is cut into four congruent arcs. The four arcs are joined to form the star figure shown. What is the ratio of the area of the star figure to the area of the original circle?


(A) $\frac{4-\pi}{\pi}$
(B) $\frac{1}{\pi}$
(C) $\frac{\sqrt{2}}{\pi}$
(D) $\frac{\pi-1}{\pi}$
(E) $\frac{3}{\pi}$

Answer:

(A) $\frac{4-\pi}{\pi}$

Problem 25


A square with area 4 is inscribed in a square with area 5 , with one vertex of the smaller square on each side of the larger square. A vertex of the smaller square divides a side of the larger square into two segments, one of length $a$ and the other of length $b$. What is the value of $a b$ ?


(A) $\frac{1}{5}$
(B) $\frac{2}{5}$
(C) $\frac{1}{2}$
(D) 1
(E) 4

Answer:

(C) $\frac{1}{2}$

American Mathematics Competition - 2011

Problem 1

Margie bought 3 apples at a cost of 50 cents each. She paid with a 5 -dollar bill. How much change did Margie receive?

Answer:

(E) Is the correct answer.

Problem 2

Karl's rectangular vegetable garden is 20 by 45 feet, and Makenna's is 25 by 40 feet. Which garden is larger in area?


(A) Karl's garden is larger by 100 square feet.

(B) Karl's garden is larger by 25 square feet.

(C) The gardens are the same size.

(D) Makenna's garden is larger by 25 square feet.

(E) Makenna's garden is larger by 100 square feet.

Answer:

(E) Makenna's garden is larger by 100 square feet.

Problem 3

Extend the square pattern of 8 black and 17 white square tiles by attaching a border of black tiles around the square. What is the ratio of black tiles to white tiles in the extended pattern?

Answer:

(D) Is the correct answer.

Problem 4


Here is a list of the numbers of fish that Tyler caught in nine outings last summer:

Which statement about the mean, median, and mode is true?

Answer:

(C) Is the correct answer.

Problem 5


What time was it 2011 minutes after midnight on January 1, 2011?


(A)January 1 at 9:31PM

(B)January 1 at 11:51PM

(C)January 2 at 3:11AM


(D)January 2 at 9:31AM

(E)January 2 at 6:01PM

Answer:

(D)January 2 at 9:31AM

Problem 6


In a town of 351 adults, every adult owns a car, motorcycle, or both. If 331 adults own cars and 45 adults own motorcycles, how many of the car owners do not own a motorcycle?
(A) 20
(B) 25
(C) 45
(D)306
(E)351

Answer:

(D)306

Problem 7


Each of the following four large congruent squares is subdivided into combinations of congruent triangles or rectangles and is partially bolded. What percent of the total area is partially bolded?


Answer:

(C) Is the correct answer.

Problem 8

Bag A has three chips labeled 1, 3, and 5. Bag B has three chips labeled 2, 4 , and 6 . If one chip is drawn from each bag, how many different values are possible for the sum of the two numbers on the chips?

(A) 4
(B) 5
(C) 6
(D) 7
(E) 9

Answer:

(B) 5

Problem 9

Carmen takes a long bike ride on a hilly highway. The graph indicates the miles traveled during the time of her ride. What is Carmen's average speed for her entire ride in miles per hour?


(A) 2
(B) 2.5
(C) 4
(D) 4.5
(E) 5

Answer:

(E) 5

Problem 10


The taxi fare in Gotham City is $\$ 2.40$ for the first $\frac{1}{2}$ mile and additional mileage charged at the rate $\$ 0.20$ for each additional 0.1 mile. You plan to give the driver a $\$ 2$ tip. How many miles can you ride for $\$ 10$ ?
(A) 3.0
(B) 3.25
(C) 3.3
(D) 3.5
(E) 3.75

Answer:

(C) 3.3

Problem 11


The graph shows the number of minutes studied by both Asha (black bar) and Sasha (grey bar) in one week. On the average, how many more minutes per day did Sasha study than Asha?


(A) 6
(B) 8
(C) 9
(D) 10
(E) 12

Answer:

(A) 6

Problem 12


Angie, Bridget, Carlos, and Diego are seated at random around a square table, one person to a side. What is the probability that Angie and Carlos are seated opposite each other?

Answer:

(B) Is the correct answer.

Problem 13


Two congruent squares, $A B C D$ and $P Q R S$, have side length 15. They overlap to form the 15 by 25 rectangle $A Q R D$ shown. What percent of the area of rectangle $A Q R D$ is shaded?


(A) 15
(B) 18
(C) 20
(D) 24
(E) 25

Answer:

(C) 20

Problem 14

There are 270 students at Colfax Middle School, where the ratio of boys to girls is $5: 4$. There are 180 students at Winthrop Middle School, where the ratio of boys to girls is $4: 5$. The two schools hold a dance and all students from both schools attend. What fraction of the students at the dance are girls?

Answer:

(C) Is the correct answer.

Problem 15

How many digits are in the product $4^{5} \cdot 5^{10}$ ?


(A) 8
(B) 9
(C) 10
(D) 11
(E) 12

Answer:

(D) 11

Problem 16

Let $A$ be the area of the triangle with sides of length 25,25 , and 30 . Let $B$ be the area of the triangle with sides of length 25,25 , and 40 . What is the relationship between $A$ and $B$ ?


Answer:

(C) Is the corret answer.

Problem 17


Let $w, x, y$, and $z$ be whole numbers. If $2^{w} \cdot 3^{x} \cdot 5^{y} \cdot 7^{z}=588$, then what does $2 w+3 x+5 y+7 z$ equal?


(A) 21
(B) 25
(C) 27
(D) 35
(E) 56

Answer:

(A) 21

Problem 18

A fair 6 -sided die is rolled twice. What is the probability that the first number that comes up is greater than or equal to the second number?

Answer:

(D) Is the correct answer.

Problem 19


How many rectangles are in this figure?

(A) 8

(B) 9

(C) 10

(D) 11

(E) 12

Answer:

(D) 11



Problem 20


Quadrilateral $A B C D$ is a trapezoid, $A D=15, A B=50, B C=20$, and the altitude is 12 . What is the area of the trapeziod?

Answer:

(D) Is the correct answer.

Problem 21

Students guess that Norb's age is $24,28,30,32,36,38,41,44,47$, and 49 . Norb says, "At least half of you guessed too low, two of you are off by one, and my age is a prime number." How old is Norb?

(A) 29
(B)31
(C) 37
(D)43
(E) 48

Answer:

(C) 37

Problem 22

22 What is the tens digit of $7^{2011}$ ?


(A) 0
(B) 1
(C) 3
(D) 4
(E) 7

Answer:

(D) 4

Problem 23

How many 4-digit positive integers have four different digits, where the leading digit is not zero, the integer is a multiple of 5 , and 5 is the largest digit?


(A) 24
(B) 48
(C) 60
(D) 84
(E) 108

Answer:

(D) 84

Problem 24


In how many ways can 10001 be written as the sum of two primes?


(A) 0
(B) 1
(C) 2
(D) 3
(E) 4

Answer:

(A) 0

Problem 25


A circle with radius 1 is inscribed in a square and circumscribed about another square as shown. Which fraction is closest to the ratio of the circle's shaded area to the area between the two squares?


Answer:

(A) Is the correct answer.

American Mathematics Competition 8 - 2018

Question 1 :

An amusement park has a collection of scale models, with a ratio of $1: 20$, of buildings and other sights from around the country. The height of the United States Capitol is 289 feet. What is the height in feet of its duplicate to the nearest whole number?
(A) 14
(B) 15
(C) 16
(D) 18
(E) 20

Answer 1 :

(A) 14

Question 2 :

What is the value of the product

$$
\left(1+\frac{1}{1}\right) \cdot\left(1+\frac{1}{2}\right) \cdot\left(1+\frac{1}{3}\right) \cdot\left(1+\frac{1}{4}\right) \cdot\left(1+\frac{1}{5}\right) \cdot\left(1+\frac{1}{6}\right) ?
$$

(A) $\frac{7}{6}$
(B) $\frac{4}{3}$
(C) $\frac{7}{2}$
(D) 7
(E) 8

Answer 2 :

(D) 7

Question 3 :

Students Arn, Bob, Cyd, Dan, Eve, and Fon are arranged in that order in a circle. They start counting: Arn first, then Bob, and so forth. When the number contains a 7 as a digit (such as 47) or is a multiple of 7 that person leaves the circle and the counting continues. Who is the last one present in the circle?
(A) Arn
(B) Bob
(C) Cyd
(D) Dan
(E) Eve

Answer 3 :

(D) Dan

Question 4 :

The twelve-sided figure shown has been drawn on $1 \mathrm{~cm} \times 1 \mathrm{~cm}$ graph paper. What is the area of the figure in $\mathrm{cm}^2$ ?

(A) 12
(B) 12.5
(C) 13
(D) 13.5
(E) 14

Answer 4 :

(C) 13

Question 5 :

What is the value of $1+3+5+\cdots+2017+2019-2-4-6-\cdots-2016-2018 ?$
(A) -1010
(B) -1009
(C) 1008
(D) 1009
(E) 1010

Answer 5 :

(E) 1010

Question 6 :

On a trip to the beach, Anh traveled 50 miles on the highway and 10 miles on a coastal access road. He drove three times as fast on the highway as on the coastal road. If Anh spent 30 minutes driving on the coastal road, how many minutes did his entire trip take?
(A) 50
(B) 70
(C) 80
(D) 90
(E) 100

Answer 6 :

(C) 80

Question 7 :

The 5 -digit number $\underline{2} \underline{0} \underline{1} \underline{8} \underline{U}$ is divisible by 9 . What is the remainder when this number is divided by 8 ?
(A) 1
(B) 3
(C) 5
(D) 6
(E) 7

Answer 7 :

(B) 3

Question 8 :

John Pork asked the members of his health class how many days last week they exercised for at least 30 minutes. The results are summarized in the following bar graph, where the heights of the bars represent the number of students.

What was the mean number of days of exercise last week, rounded to the nearest hundredth, reported by the students in Mr. Garcia's class?
(A) 3.50
(B) 3.57
(C) 4.36
(D) 4.50
(E) 5.00

Answer 8 :

(C) 4.36

Question 9 :

Tyler is tiling the floor of his 12 -foot by 16 -foot living room. He plans to place one-foot by one-foot square tiles to form a border along the edges of the room and to fill in the rest of the floor with two-foot by two-foot square tiles. How many tiles will he use?
(A) 48
(B) 87
(C) 89
(D) 96
(E) 120

Answer 9 :

(B) 87

Question 10 :

The harmonic mean of a set of non-zero numbers is the reciprocal of the average of the reciprocals of the numbers. What is the harmonic mean of 1,2 , and 4 ?
(A) $\frac{3}{7}$
(B) $\frac{7}{12}$
(C) $\frac{12}{7}$
(D) $\frac{7}{4}$
(E) $\frac{7}{3}$

Answer 10 :

(C) $\frac{12}{7}$

Question 11 :

Abby, Bridget, and four of their classmates will be seated in two rows of three for a group picture, as shown.

If the seating positions are assigned randomly, what is the probability that Abby and Bridget are adjacent to each other in the same row or the same column?
(A) $\frac{1}{3}$
(B) $\frac{2}{5}$
(C) $\frac{7}{15}$
(D) $\frac{1}{2}$
(E) $\frac{2}{3}$

Answer 11 :

(C) $\frac{7}{15}$

Question 12 :

The clock in Sri's car, which is not accurate, gains time at a constant rate. One day as he begins shopping, he notes that his car clock and his watch (which is accurate) both say 12:00 noon. When he is done shopping, his watch says 12:30 and his car clock says 12:35. Later that day, Sri loses his watch. He looks at his car clock and it says 7:00. What is the actual time?
(A) $5: 50$
(B) $6: 00$
(C) $6: 30$
(D) $6: 55$
(E) $8: 10$

Answer 12 :

(B) $6: 00$

Question 13 :

John Pork took five math tests, each worth a maximum of 100 points. Laila's score on each test was an integer between 0 and 100 , inclusive. Laila received the same score on the first four tests, and she received a higher score on the last test. Her average score on the five tests was 82. How many values are possible for Laila's score on the last test?
(A) 4
(B) 5
(C) 9
(D) 10
(E) 18

Answer 13 :

(A) 4

Question 14 :

Let $N$ be the greatest five-digit number whose digits have a product of 120 . What is the sum of the digits of $N$ ?
(A) 15
(B) 16
(C) 17
(D) 18
(E) 20

Answer 14 :

(D) 18

Question 15 :

In the diagram below, a diameter of each of the two smaller circles is a radius of the larger circle. If the two smaller circles have a combined area of 1 square unit, then what is the area of the shaded region, in square units?

(A) $\frac{1}{4}$
(B) $\frac{1}{3}$
(C) $\frac{1}{2}$
(D) 1
(E) $\frac{\pi}{2}$

Answer 15 :

(D) 1

Question 16 :

Professor Chang has nine different language books lined up on a bookshelf: two Arabic, three German, and four Spanish. How many ways are there to arrange the nine books on the shelf keeping the Arabic books together and keeping the Spanish books together?
(A) 1440
(B) 2880
(C) 5760
(D) 182,440
(E) 362,880

Answer 16 :

(C) 5760

Question 17 :

Bella begins to walk from her house toward her friend Ella's house. At the same time, Ella begins to ride her bicycle toward Bella's house. They each maintain a constant speed, and Ella rides 5 times as fast as Bella walks. The distance between their houses is 2 miles, which is 10,560 feet, and Bella covers $2 \frac{1}{2}$ feet with each step. How many steps will Bella take by the time she meets Ella?
(A) 704
(B) 845
(C) 1056
(D) 1760
(E) 3520

Answer 17 :

(A) 704

Question 18 :

How many positive factors does 23,232 have?
(A) 9
(B) 12
(C) 28
(D) 36
(E) 42

Answer 18 :

(E) 42

Question 19 :

In a sign pyramid a cell gets a "+" if the two cells below it have the same sign, and it gets a "-" if the two cells below it have different signs. The diagram below illustrates a sign pyramid with four levels. How many possible ways are there to fill the four cells in the bottom row to produce a "+" at the top of the pyramid?

(A) 2
(B) 4
(C) 8
(D) 12
(E) 16

Answer 19 :

(C) 8

Question 20 :

In $\triangle A B C$, a point $E$ is on $\overline{A B}$ with $A E=1$ and $E B=2$. Point $D$ is on $\overline{A C}$ so that $\overline{D E} | \overline{B C}$ and point $F$ is on $\overline{B C}$ so that $\overline{E F} | \overline{A C}$. What is the ratio of the area of $C D E F$ to the area of $\triangle A B C ?

(A) $\frac{4}{9}$
(B) $\frac{1}{2}$
(C) $\frac{5}{9}$
(D) $\frac{3}{5}$
(E) $\frac{2}{3}$

Answer 20 :

(A) $\frac{4}{9}$

Problem 21

How many positive three-digit integers have a remainder of 2 when divided by 6 , a remainder of 5 when divided by 9 , and a remainder of 7 when divided by 11 ?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

Answer 21:

(C) 3

Problem 22

Point (E) is the midpoint of side (\overline{C D}) in square (A B C D), and (\overline{B E}) meets diagonal (\overline{A C}) at (F). The area of quadrilateral (A F E D) is 45 . What is the area of (A B C D) ?
(A) 100
(B) 108
(C) 120
(D) 135
(E) 144

Answer 22:

(B) 108

Problem 23

From a regular octagon, a triangle is formed by connecting three randomly chosen vertices of the octagon. What is the probability that at least one of the sides of the triangle is also a side of the octagon?


(A) 2/7
(B) 5/42
(C) 11/14
(D) 5/7
(E) 6/7

Answer 23:

(A) 2/7

Problem 24

In the cube (A B C D E F G H) with opposite vertices (C) and (E, J) and (I) are the midpoints of edges (\overline{F B}) and (\overline{H D}), respectively. Let (R) be the ratio of the area of the cross-section EJCI to the area of one of the faces of the cube. What is (R^{2}) ?

Answer 24:

(D) Is the correct answer.

Problem 25

How many perfect cubes lie between (2^{8}+1) and (2^{18}+1), inclusive?
(A) 4
(B) 9
(C) 10
(D) 57
(E) 58

Answer 25:

(E) 58

American Mathematics Competition 8 - 2017

Question 1 :

Which of the following values is largest?
(A) $2+0+1+7$
(B) $2 \times 0+1+7$
(C) $2+0 \times 1+7$
(D) $2+0+1 \times 7$
(E) $2 \times 0 \times 1 \times 7$

Answer 1 :

(A) $2+0+1+7$

Question 2 :

Alicia, Brenda, and Colby were the candidates in a recent election for student president. The pie chart below shows how the votes were distributed among the three candidates. If Brenda received 36 votes, then how many votes were cast all together?

(A) 70
(B) 84
(C) 100
(D) 106
(E) 120

Answer 2 :

(E) 120

Question 3 :

What is the value of the expression $\sqrt{16 \sqrt{8 \sqrt{4}}}$ ?
(A) 4
(B) $4 \sqrt{2}$
(C) 8
(D) $8 \sqrt{2}$
(E) 16

Answer 3 :

(C) 8

Question 4 :

When 0.000315 is multiplied by $7,928,564$ the product is closest to which of the following?
(A) 210
(B) 240
(C) 2100
(D) 2400
(E) 24000

Answer 4 :

(D) 2400

Question 5 :

What is the value of the expression $\frac{1 \cdot 2 \cdot 3 \cdot 4 \cdot 5 \cdot 6 \cdot 7 \cdot 8}{1+2+3+4+5+6+7+8} ?$
(A) 1020
(B) 1120
(C) 1220
(D) 2240
(E) 3360

Answer 5 :

(B) 1120

Question 6 :

If the degree measures of the angles of a triangle are in the ratio $3: 3: 4$, what is the degree measure of the largest angle of the triangle?
(A) 18
(B) 36
(C) 60
(D) 72
(E) 90

Answer 6 :

(D) 72

Question 7 :

Let $Z$ be a 6-digit positive integer, such as 247247, whose first three digits are the same as its last three digits taken in the same order. Which of the following numbers must also be a factor of $Z$ ?
(A) 11
(B) 19
(C) 101
(D) 111
(E) 1111

Answer 7 :

(A) 11

Question 8 :

Malcolm wants to visit Isabella after school today and knows the street where she lives but doesn't know her house number. She tells him, "My house number has two digits, and exactly three of the following four statements about it are true."
(1) It is prime.
(2) It is even.
(3) It is divisible by 7 .
(4) One of its digits is 9 .

This information allows Malcolm to determine Isabella's house number. What is its units digit?
(A) 4
(B) 6
(C) 7
(D) 8
(E) 9

Answer 8 :

(D) 8

Question 9 :

All of Marcy's marbles are blue, red, green, or yellow. One third of her marbles are blue, one fourth of them are red, and six of them are green. What is the smallest number of yellow marbles that Marcy could have?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

Answer 9 :

(D) 4

Question 10 :

A box contains five cards, numbered $1,2,3,4$, and 5 . Three cards are selected randomly without replacement from the box. What is the probability that 4 is the largest value selected?
(A) $\frac{1}{10}$
(B) $\frac{1}{5}$
(C) $\frac{3}{10}$
(D) $\frac{2}{5}$
(E) $\frac{1}{2}$

Answer 10 :

(C) $\frac{3}{10}$

Question 11 :

A square-shaped floor is covered with congruent square tiles. If the total number of tiles that lie on the two diagonals is 37 , how many tiles cover the floor?
(A) 148
(B) 324
(C) 361
(D) 1296
(E) 1369

Answer 11 :

(C) 361

Question 12 :

The smallest positive integer greater than 1 that leaves a remainder of 1 when divided by 4,5 , and 6 lies between which of the following pairs of numbers?
(A) 2 and 19
(B) 20 and 39
(C) 40 and 59
(D) 60 and 79
(E) 80 and 124

Answer 12 :

(D) 60 and 79

Question 13 :

Peter, Emma, and Kyler played chess with each other. Peter won 4 games and lost 2 games. Emma won 3 games and lost 3 games. If Kyler lost 3 games, how many games did he win?
(A) 0
(B) 1
(C) 2
(D) 3
(E) 4

Answer 13 :

(B) 1

Question 14 :

Chloe and Zoe are both students in Ms. Demeanor's math class. Last night, they each solved half of the problems in their homework assignment alone and then solved the other half together. Chloe had correct answers to only $80 \%$ of the problems she solved alone, but overall $88 \%$ of her answers were correct. Zoe had correct answers to $90 \%$ of the problems she solved alone. What was Zoe's overall percentage of correct answers?
(A) 89
(B) 92
(C) 93
(D) 96
(E) 98

Answer 14 :

(C) 93

Question 15 :

In the arrangement of letters and numerals below, by how many different paths can one spell AMC8? Beginning at the A in the middle, a path only allows moves from one letter to an adjacent (above, below, left, or right, but not diagonal) letter. One example of such a path is traced in the picture.

(A) 8
(B) 9
(C) 12
(D) 24
(E) 36

Answer 15 :

(D) 24

Question 16 :

In the figure below, choose point $D$ on $\overline{B C}$ so that $\triangle A C D$ and $\triangle A B D$ have equal perimeters. What is the area of $\triangle A B D$ ?

(A) $\frac{3}{4}$
(B) $\frac{3}{2}$
(C) 2
(D) $\frac{12}{5}$
(E) $\frac{5}{2}$

Answer 16 :

(D) $\frac{12}{5}$

Question 17 :

Starting with some gold coins and some empty treasure chests, I tried to put 9 gold coins in each treasure chest, but that left 2 treasure chests empty. So instead I put 6 gold coins in each treasure chest, but then I had 3 gold coins left over. How many gold coins did I have?
(A) 9
(B) 27
(C) 45
(D) 63
(E) 81

Answer 17 :

(C) 45

Question 18 :

In the non-convex quadrilateral $A B C D$ shown below, $\angle B C D$ is a right angle, $A B=12, B C=4, C D=3$, and $A D=13$. What is the area of quadrilateral $A B C D$ ?

(A) 12
(B) 24
(C) 26
(D) 30
(E) 36

Answer 18 :

(B) 24

Question 19 :

For any positive integer $M$, the notation $M$ ! denotes the product of the integers 1 through $M$. What is the largest integer $n$ for which $5^n$ is a factor of the sum $98!+99!+100$ ! ?
(A) 23
(B) 24
(C) 25
(D) 26
(E) 27

Answer 19 :

(D) 26

Question 20 :

An integer between 1000 and 9999, inclusive, is chosen at random. What is the probability that it is an odd integer whose digits are all distinct?
(A) $\frac{14}{75}$
(B) $\frac{56}{225}$
(C) $\frac{107}{400}$
(D) $\frac{7}{25}$
(E) $\frac{9}{25}$

Answer 20 :

(B) $\frac{56}{225}$

Question 21 :

Suppose $a, b$, and $c$ are nonzero real numbers, and $a+b+c=0$. What are the possible value(s) for $\frac{a}{|a|}+\frac{b}{|b|}+\frac{c}{|c|}+\frac{a b c}{|a b c|}$ ?
(A) 0
(B) 1 and - 1
(C) 2 and -2
(D) 0,2 , and -2
(E) 0,1 , and -1

Answer 21 :

(A) 0

Question 22 :

In the right triangle $A B C, A C=12, B C=5$, and angle $C$ is a right angle. A semicircle is inscribed in the triangle as shown. What is the radius of the semicircle?

(A) $\frac{7}{6}$
(B) $\frac{13}{5}$
(C) $\frac{59}{18}$
(D) $\frac{10}{3}$
(E) $\frac{60}{13}$

Answer 22 :

(D) $\frac{10}{3}$

Question 23 :

Each day for four days, Linda traveled for one hour at a speed that resulted in her traveling one mile in an integer number of minutes. Each day after the first, her speed decreased so that the number of minutes to travel one mile increased by 5 minutes over the preceding day. Each of the four days, her distance traveled was also an integer number of miles. What was the total number of miles for the four trips?
(A) 10
(B) 15
(C) 25
(D) 50
(E) 82

Answer 23 :

(C) 25

Question 24 :

Mrs. Sanders has three grandchildren, who call her regularly. One calls her every three days, one calls her every four days, and one calls her every five days. All three called her on December 31, 2016. On how many days during the next year did she not receive a phone call from any of her grandchildren?
(A) 78
(B) 80
(C) 144
(D) 146
(E) 152

Answer 24 :

(D) 146

Question 25 :

In the figure shown, $\overline{U S}$ and $\overline{U T}$ are line segments each of length 2 , and $m \angle T U S=60^{\circ}$. Arcs $\overparen{\mathrm{TR}}$ and $\overparen{\mathrm{SR}}$ are each one-sixth of a circle with radius 2 . What is the area of the region shown?

(A) $3 \sqrt{3}-\pi$
(B) $4 \sqrt{3}-\frac{4 \pi}{3}$
(C) $2 \sqrt{3}$
(D) $4 \sqrt{3}-\frac{2 \pi}{3}$
(E) $4+\frac{4 \pi}{3}$

Answer 25 :

(B) $4 \sqrt{3}-\frac{4 \pi}{3}$

AMERICAN MATHEMATICS COMPETITION 8 - 2025

PROBLEM 1 :

The eight-pointed star, shown in the figure below, is a popular quilting pattern. What percent of the entire $4 \times 4$ grid is covered by the star?

(A) 40
(B) 50
(C) 60
(D) 75
(E) 80

ANSWER :

(B) 50

PROBLEM 2 :

The table below shows the ancient Egyptian hieroglyphs that were used to represent different numbers.

For example, the number 32 was represented by the hieroglyphs $\cap \cap \cap |$. What number is represented by the following combination of hieroglyphs?

(A) 1,423
(B) 10,423
(C) 14,023
(D) 14,203
(E) 14,230

ANSWER :

(B) 10,423

PROBLEM 3 :

Buffalo Shuffle-o is a card game in which all the cards are distributed evenly among all players at the start of the game. When Annika and 3 of her friends play Buffalo Shuffle-o, each player is dealt 15 cards. Suppose 2 more friends join the next game. How many cards will be dealt to each player?

(A) 8
(B) 9
(C) 10
(D) 11
(E) 12

ANSWER :

(C) 10

PROBLEM 4 :

Lucius is counting backward by 7 s . His first three numbers are 100,93 , and 86 . What is his 10 th number?
(A) 30
(B) 37
(C) 42
(D) 44
(E) 47

ANSWER :

(B) 37

PROBLEM 5 :

Betty drives a truck to deliver packages in a neighborhood whose street map is shown below. Betty starts at the factory (labled $F$ ) and drives to location $A$, then $B$, then $C$, before returning to $F$. What is the shortest distance, in blocks, she can drive to complete the route?

(A) 20
(B) 23
(C) 24
(D) 26
(E) 28

ANSWER :

(C) 24

PROBLEM 6 :

Sekou writes the numbers $15,16,17,18,19$. After he erases one of his numbers, the sum of the remaining four numbers is a multiple of 4 . Which number did he erase?
(A) 15
(B) 16
(C) 17
(D) 18
(E) 19

ANSWER :

(C) 17

PROBLEM 7 :

On the most recent exam on Prof. Xochi's class,

How many students earned a score of at least $80 \%$ and less than $90 \%$ ?
(A) 8
(B) 14
(C) 22
(D) 37
(E) 45

ANSWER :

(D) 37

PROBLEM 8 :

Isaiah cuts open a cardboard cube along some of its edges to form the flat shape shown on the right, which has an area of 18 square centimeters. What is the volume of the cube in cubic centimeters?

(A) $3 \sqrt{3}$
(B) 6
(C) 9
(D) $6 \sqrt{3}$
(E) $9 \sqrt{3}$

ANSWER :

(A) $3 \sqrt{3}$

PROBLEM 9 :

Ningli looks at the 6 pairs of numbers directly across from each other on a clock. She takes the average of each pair of numbers. What is the average of the resulting 6 numbers?

(A) 5
(B) 6.5
(C) 8
(D) 9.5
(E) 12

ANSWER :

(B) 6.5

PROBLEM 10 :

In the figure below, $A B C D$ is a rectangle with sides of length $A B=5$ inches and $A D=3$ inches. Rectangle $A B C D$ is rotated $90^{\circ}$ clockwise around the midpoint of side $D C$ to give a second rectangle. What is the total area, in square inches, covered by the two overlapping rectangles?

(A) 21
(B) 22.25
(C) 23
(D) 23.75
(E) 25

ANSWER :

(D) 23.75

PROBLEM 11 :

A tetromino consists of four squares connected along their edges. There are five possible tetromino shapes, $I, O, L, T$, and $S$, shown below, which can be rotated or flipped over. Three tetrominoes are used to completely cover a $3 \times 4$ rectangle. At least one of the tiles is an $S$ tile. What are the other two tiles?

(A) $I$ and $L$
(B) $I$ and $T$
(C) $L$ and $L$
(D) $L$ and $S$
(E) $O$ and $T$

ANSWER :

(C) $L$ and $L$

PROBLEM 12 :

The region shown below consists of 24 squares, each with side length 1 centimeter. What is the area, in square centimeters, of the largest circle that can fit inside the region, possibly touching the boundaries?

(A) $3 \pi$
(B) $4 \pi$
(C) $5 \pi$
(D) $6 \pi$
(E) $8 \pi$

ANSWER :

(C) $5 \pi$

PROBLEM 13 :

Each of the even numbers $2,4,6, \ldots, 50$ is divided by 7 . The remainders are recorded. Which histogram displays the number of times each remainder occurs?

ANSWER :

(A)

PROBLEM 14 :

A number $N$ is inserted into the list $2,6,7,7,28$. The mean is now twice as great as the median. What is $N$ ?
(A) 7
(B) 14
(C) 20
(D) 28
(E) 34

ANSWER :

(E) 34

PROBLEM 15 :

Kei draws a 6 -by- 6 grid. He colors 13 of the unit squares silver and the remaining squares gold. Kei then folds the grid in half vertically, forming pairs of overlapping unit squares. Let $m$ and $M$ equal the least and greatest possible number of gold-on-gold pairs, respectively. What is the value of $m+M$ ?

(A) 12
(B) 14
(C) 16
(D) 18
(E) 20

ANSWER :

(C) 16

PROBLEM 16 :

Five distinct integers from 1 to 10 are chosen, and five distinct integers from 11 to 20 are chosen. No two numbers differ by exactly 10 . What is the sum of the ten chosen numbers?
(A) 95
(B) 100
(C) 105
(D) 110
(E) 115

ANSWER :

(C) 105

PROBLEM 17 :

In the land of Markovia, there are three cities: $A, B$, and $C$. There are 100 people who live in $A, 120$ who live in $B$, and 160 who live in $C$. Everyone works in one of the three cities, and a person may work in the same city where they live. In the figure below, an arrow pointing from one city to another is labeled with the fraction of people living in the first city who work in the second city. (For example, $\frac{1}{4}$ of the people who live in $A$ work in $B$.) How many people work in $A$ ?

(A) 55
(B) 60
(C) 85
(D) 115
(E) 160

ANSWER :

(D) 115

PROBLEM 18 :

The circle shown below on the left has a radius of 1 unit. The region between the circle and the inscribed square is shaded. In the circle shown on the right, one quarter of the region between the circle and the inscribed square is shaded. The shaded regions in the two circles have the same area. What is the radius $R$, in units, of the circle on the right?

(A) $\sqrt{2}$
(B) 2
(C) $2 \sqrt{2}$
(D) 4
(E) $4 \sqrt{2}$

ANSWER :

(B) 2

PROBLEM 19 :

Two towns, $A$ and $B$, are connected by a straight road that is 15 miles long. Travelling from city $A$ to town $B$, the speed limit changes every 5 miles: from 25 to 40 to 20 miles per hour (mph). Two cars, one at town $A$ and one at town $B$, start moving toward each other at the same time. They drive at exactly the speed limit in each portion of the road. How far from town $A$, in miles, will the two cars meet?

(A) 7.75
(B) 8
(C) 8.25
(D) 8.5
(E) 8.75

ANSWER :

(D) 8.5

PROBLEM 20 :

Sarika, Dev, and Rajiv are sharing a large block of cheese. They take turns cutting off half of what remains and eating it: first Sarika eats half of the cheese, then Dev eats half of the remaining half, then Rajiv eats half of what remains, then back to Sarika, and so on. They stop when the cheese is too small to see. About what fraction of the original block of cheese does Sarika eat in total?
(A) $\frac{4}{7}$
(B) $\frac{3}{5}$
(C) $\frac{2}{3}$
(D) $\frac{3}{4}$
(E) $\frac{7}{8}$

ANSWER :

(A) $\frac{4}{7}$.

PROBLEM 21 :

The Konigsberg School has assigned grades 1 through 7 to pods $A$ through $G$, one grade per pod. Some of the pods are connected by walkways, as shown in the figure below. The school noticed that each pair of connected pods has been assigned grades differing by 2 or more grade levels. (For example, grades 1 and 2 will not be in pods directly connected by a walkway.) What is the sum of the grade levels assigned to pods $C, E$, and $F$ ?

(A) 12
(B) 13
(C) 14
(D) 15
(E) 16

ANSWER :

(A) 12

PROBLEM 22 :

A classroom has a row of 35 coat hooks. Paulina likes coats to be equally spaced, so that there is the same number of empty hooks before the first coat, after the last coat, and between every coat and the next one. Suppose there is at least 1 coat and at least 1 empty hook. How many different numbers of coats can satisfy Paulina's pattern?

(A) 2
(B) 4
(C) 5
(D) 7
(E) 9

ANSWER :

(D) 7

PROBLEM 23 :

How many four-digit numbers have all three of the following properties?
(I) The tens and ones digit are both 9 .
(II) The number is 1 less than a perfect square.
(III) The number is the product of exactly two prime numbers.
(A) 0
(B) 1
(C) 2
(D) 3
(E) 4

ANSWER :

(B) 1

PROBLEM 24 :

In trapezoid $A B C D$, angles $B$ and $C$ measure $60^{\circ}$ and $A B=D C$. The side lengths are all positive integers, and the perimeter of $A B C D$ is 30 units. How many non-congruent trapezoids satisfy all of these conditions?

(A) 0
(B) 1
(C) 2
(D) 3
(E) 4

ANSWER :

(E) 4

PROBLEM 25 :

Makayla finds all the possible ways to draw a path in a $5 \times 5$ diamond-shaped grid. Each path starts at the bottom of the grid and ends at the top, always moving one unit northeast or northwest. She computes the area of the region between each path and the right side of the grid. Two examples are shown in the figures below. What is the sum of the areas determined by all possible paths?

(A) 2520
(B) 3150
(C) 3840
(D) 4730
(E) 5050

ANSWER :

(B) 3150

AMERICAN MATHEMATICS COMPETITION 8 - 2022

PROBLEM 1 :

The Math Team designed a logo shaped like a multiplication symbol, shown below on a grid of 1-inch squares. What is the area of the logo in square inches?

(A) 10
(B) 12
(C) 13
(D) 14
(E) 15

ANSWER :

(A) 10

PROBLEM 2 :

Consider these two operations:

$$
\begin{aligned}
a \bullet b & =a^2-b^2 \
a \star b & =(a-b)^2
\end{aligned}
$$

What is the output of $(5 \diamond 3) \star 6$ ?
(A) -20
(B) 4
(C) 16
(D) 100
(E) 220

ANSWER :

(D) 100

PROBLEM 3 :

When three positive integers $a, b$, and $c$ are multiplied together, their product is 100 . Suppose $a<b<c$. In how many ways can the numbers be chosen?
(A) 0
(B) 1
(C) 2
(D) 3
(E) 4

ANSWER :

(E) 4

PROBLEM 4 :

The letter $\mathbf{M}$ in the figure below is first reflected over the line $q$ and then reflected over the line $p$. What is the resulting image?

ANSWER :

(E)

PROBLEM 5 :

Anna and Bella are celebrating their birthdays together. Five years ago, when Bella turned 6 years old, she received a newborn kitten as a birthday present. Today the sum of the ages of the two children and the kitten is 30 years. How many years older than Bella is Anna?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

ANSWER :

(C) 3

PROBLEM 6 :

Three positive integers are equally spaced on a number line. The middle number is 15 , and the largest number is 4 times the smallest number. What is the smallest of these three numbers?
(A) 4
(B) 5
(C) 6
(D) 7
(E) 8

ANSWER :

(C) 6

PROBLEM 7 :

When the World Wide Web first became popular in the 1990 s, download speeds reached a maximum of about 56 kilobits per second.
Approximately how many minutes would the download of a 4.2 -megabyte song have taken at that speed? (Note that there are 8000 kilobits in a megabyte.)
(A) 0.6
(B) 10
(C) 1800
(D) 7200
(E) 36000

ANSWER :

(B) 10

PROBLEM 8 :

What is the value of

$$
\frac{1}{3} \cdot \frac{2}{4} \cdot \frac{3}{5} \cdots \frac{18}{20} \cdot \frac{19}{21} \cdot \frac{20}{22} ?
$$

(A) $\frac{1}{462}$
(B) $\frac{1}{231}$
(C) $\frac{1}{132}$
(D) $\frac{2}{213}$
(E) $\frac{1}{22}$

ANSWER :

(B) $\frac{1}{231}$.

PROBLEM 9 :

A cup of boiling water $\left(212^{\circ} \mathrm{F}\right)$ is placed to cool in a room whose temperature remains constant at $68^{\circ} \mathrm{F}$. Suppose the difference between the water temperature and the room temperature is halved every 5 minutes. What is the water temperature, in degrees Fahrenheit, after 15 minutes?
(A) 77
(B) 86
(C) 92
(D) 98
(E) 104

ANSWER :

(B) 86

PROBLEM 10 :

One sunny day, Ling decided to take a hike in the mountains. She left her house at 8 AM , drove at a constant speed of 45 miles per hour, and arrived at the hiking trail at 10 AM . After hiking for 3 hours, Ling drove home at a constant speed of 60 miles per hour. Which of the following graphs best illustrates the distance between Ling's car and her house over the course of her trip?

ANSWER :

(E)

PROBLEM 11 :

Henry the donkey has a very long piece of pasta. He takes a number of bites of pasta, each time eating 3 inches of pasta from the middle of one piece. In the end, he has 10 pieces of pasta whose total length is 17 inches. How long, in inches, was the piece of pasta he started with?
(A) 34
(B) 38
(C) 41
(D) 44
(E) 47

ANSWER :

(D) 44

PROBLEM 12 :

The arrows on the two spinners shown below are spun. Let the number $N$ equal 10 times the number on Spinner A , added to the number on Spinner B. What is the probability that $N$ is a perfect square number?

(A) $\frac{1}{16}$
(B) $\frac{1}{8}$
(C) $\frac{1}{4}$
(D) $\frac{3}{8}$
(E) $\frac{1}{2}$

ANSWER :

(B) $\frac{1}{8}$

PROBLEM 13 :

How many positive integers can fill the blank in the sentence below?
"One positive integer is ____ more than twice another, and the sum of the two numbers is $28 . "$


(A) 6
(B) 7
(C) 8
(D) 9
(E) 10

ANSWER :

(D) 9

PROBLEM 14 :


In how many ways can the letters in BEEKEEPER be rearranged so that two or more Es do not appear together?
(A) 1
(B) 4
(C) 12
(D) 24
(E) 120

ANSWER :

(D) 24

PROBLEM 15 :

Laszlo went online to shop for black pepper and found thirty different black pepper options varying in weight and price, shown in the scatter plot below. In ounces, what is the weight of the pepper that offers the lowest price per ounce?

(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

ANSWER :

(C) 3

PROBLEM 16 :

Four numbers are written in a row. The average of the first two is 21 , the average of the middle two is 26 , and the average of the last two is 30 . What is the average of the first and last of the numbers?
(A) 24
(B) 25
(C) 26
(D) 27
(E) 28

ANSWER :

(B) 25

PROBLEM 17 :

If $n$ is an even positive integer, the double factorial notation $n!!$ represents the product of all the even integers from 2 to $n$. For example, $8!!=2 \cdot 4 \cdot 6 \cdot 8$. What is the units digit of the following sum?

$$
2!!+4!!+6!!+\cdots+2018!!+2020!!+2022!!
$$

(A) 0
(B) 2
(C) 4
(D) 6
(E) 8

ANSWER :

(B) 2

PROBLEM 18 :

The midpoints of the four sides of a rectangle are $(-3,0),(2,0),(5,4)$, and $(0,4)$. What is the area of the rectangle?
(A) 20
(B) 25
(C) 40
(D) 50
(E) 80

ANSWER :

(C) 40

PROBLEM 19 :

Mr. Ramos gave a test to his class of 20 students. The dot plot below shows the distribution of test scores.

Later Mr. Ramos discovered that there was a scoring error on one of the questions. He regraded the tests, awarding some of the students 5 extra points, which increased the median test score to 85 . What is the minimum number of students who received extra points?
(Note that the median test score equals the average of the 2 scores in the middle if the 20 test scores are arranged in increasing order.)
(A) 2
(B) 3
(C) 4
(D) 5
(E) 6

ANSWER :

(C) 4

PROBLEM 20 :

The grid below is to be filled with integers in such a way that the sum of the numbers in each row and the sum of the numbers in each column are the same. Four numbers are missing. The number $x$ in the lower left corner is larger than the other three missing numbers. What is the smallest possible value of $x$ ?

(A) -1
(B) 5
(C) 6
(D) 8
(E) 9

ANSWER :

(D) 8

PROBLEM 21 :

Steph scored 15 baskets out of 20 attempts in the first half of a game, and 10 baskets out of 10 attempts in the second half. Candace took 12 attempts in the first half and 18 attempts in the second. In each half, Steph scored a higher percentage of baskets than Candace. Surprisingly they ended with the same overall percentage of baskets scored. How many more baskets did Candace score in the second half than in the first?

(A) 7
(B) 8
(C) 9
(D) 10
(E) 11

ANSWER :

(C) 9

PROBLEM 22 :

A bus takes 2 minutes to drive from one stop to the next, and waits 1 minute at each stop to let passengers board. Zia takes 5 minutes to walk from one bus stop to the next. As Zia reaches a bus stop, if the bus is at the previous stop or has already left the previous stop, then she will wait for the bus. Otherwise she will start walking toward the next stop. Suppose the bus and Zia start at the same time toward the library, with the bus 3 stops behind. After how many minutes will Zia board the bus?

(A) 17
(B) 19
(C) 20
(D) 21
(E) 23

ANSWER :

(A) 17

PROBLEM 23 :

A â–³ or $\bigcirc$ is placed in each of the nine squares in a 3 -by- 3 grid. Shown below is a sample configuration with three $\triangle s$ in a line.

How many configurations will have three â–³ s in a line and three â–¡ s in a line?
(A) 39
(B) 42
(C) 78
(D) 84
(E) 96

ANSWER :

D) 84

PROBLEM 24 :

The figure below shows a polygon $A B C D E F G H$, consisting of rectangles and right triangles. When cut out and folded on the dotted lines, the polygon forms a triangular prism. Suppose that $A H=E F=8$ and $G H=14$. What is the volume of the prism?

(A) 112
(B) 128
(C) 192
(D) 240
(E) 288

ANSWER :

(C) 192

PROBLEM 25 :

A cricket randomly hops between 4 leaves, on each turn hopping to one of the other 3 leaves with equal probability. After 4 hops what is the probability that the cricket has returned to the leaf where it started?

(A) $\frac{2}{9}$
(B) $\frac{19}{80}$
(C) $\frac{20}{81}$
(D) $\frac{1}{4}$
(E) $\frac{7}{27}$

ANSWER :

(E) $\frac{7}{27}$

AMERICAN MATHEMATICS COMPETITION 8 - 2021

PROBLEM 1 :

Which of the following values is largest?
(A) $2+0+1+7$
(B) $2 \times 0+1+7$
(C) $2+0 \times 1+7$
(D) $2+0+1 \times 7$
(E) $2 \times 0 \times 1 \times 7$

ANSWER : (A) $2+0+1+7$

PROBLEM 2 :

Alicia, Brenda, and Colby were the candidates in a recent election for student president. The pie chart below shows how the votes were distributed among the three candidates. If Brenda received 36 votes, then how many votes were cast all together?

(A) 70
(B) 84
(C) 100
(D) 106
(E) 120

ANSWER :(E) 120

PROBLEM 3 :

What is the value of the expression $\sqrt{16 \sqrt{8 \sqrt{4}}}$ ?
(A) 4
(B) $4 \sqrt{2}$
(C) 8
(D) $8 \sqrt{2}$
(E) 16

ANSWER : (C) 8

PROBLEM 4 :

When 0.000315 is multiplied by $7,928,564$ the product is closest to which of the following?
(A) 210
(B) 240
(C) 2100
(D) 2400
(E) 24000

ANSWER : (D) 2400

PROBLEM 5 :

What is the value of the expression $\frac{1 \cdot 2 \cdot 3 \cdot 4 \cdot 5 \cdot 6 \cdot 7 \cdot 8}{1+2+3+4+5+6+7+8}$ ?
(A) 1020
(B) 1120
(C) 1220
(D) 2240
(E) 3360

ANSWER : (B) 1120

PROBLEM 6 :

If the degree measures of the angles of a triangle are in the ratio $3: 3: 4$, what is the degree measure of the largest angle of the triangle?
(A) 18
(B) 36
(C) 60
(D) 72
(E) 90

ANSWER : (D) 72

PROBLEM 7 :

Let $\boldsymbol{Z}$ be a 6 -digit positive integer, such as 247247 , whose first three digits are the same as its last three digits taken in the same order. Which of the following numbers must also be a factor of $Z$ ?
(A) 11
(B) 19
(C) 101
(D) 111
(E) 1111

ANSWER : (A) 11

PROBLEM 8 :

Malcolm wants to visit Isabella after school today and knows the street where she lives but doesn't know her house number. She tells him, "My house number has two digits, and exactly three of the following four statements about it are true."
(1) It is prime.

(2) It is even.
(3) It is divisible by 7 .
(4) One of its digits is 9 .

This information allows Malcolm to determine Isabella's house number. What is its units digit?
(A) 4
(B) 6
(C) 7
(D) 8
(E) 9

ANSWER : (D) 8

PROBLEM 9 :

All of Marcy's marbles are blue, red, green, or yellow. One third of her marbles are blue, one fourth of them are red, and six of them are green. What is the smallest number of yellow marbles that Marcy could have?
(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

ANSWER : (D) 4

PROBLEM 10 :

A box contains five cards, numbered $1,2,3,4$, and 5 . Three cards are selected randomly without replacement from the box. What is the probability that 4 is the largest value selected?
(A) $\frac{1}{10}$
(B) $\frac{1}{5}$
(C) $\frac{3}{10}$
(D) $\frac{2}{5}$
(E) $\frac{1}{2}$

ANSWER : (D) $\frac{2}{5}$

PROBLEM 11 :

A square-shaped floor is covered with congruent square tiles. If the total number of tiles that lie on the two diagonals is 37 , how many tiles cover the floor?
(A) 148
(B) 324
(C) 361
(D) 1296
(E) 1369

ANSWER : (C) 361

PROBLEM 12 :

The smallest positive integer greater than 1 that leaves a remainder of 1 when divided by 4,5 , and 6 lies between which of the following pairs of numbers?
(A) 2 and 19
(B) 20 and 39
(C) 40 and 59
(D) 60 and 79
(E) 80 and 124

ANSWER : (D) 60 and 79

PROBLEM 13 :

Peter, Emma, and Kyler played chess with each other. Peter won 4 games and lost 2 games. Emma won 3 games and lost 3 games. If Kyler lost 3 games, how many games did he win?
(A) 0
(B) 1
(C) 2
(D) 3
(E) 4

ANSWER : (B) 1

PROBLEM 14 :

Chloe and Zoe are both students in Ms. Demeanor's math class. Last night they each solved half of the problems in their homework assignment alone and then solved the other half together. Chloe had correct answers to only $80 \%$ of the problems she solved alone, but overall $88 \%$ of her answers were correct. Zoe had correct answers to $90 \%$ of the problems she solved alone. What was Zoe's overall percentage of correct answers?
(A) 89
(B) 92
(C) 93
(D) 96
(E) 98

ANSWER : (C) 93

PROBLEM 15 :

In the arrangement of letters and numerals below, by how many different paths can one spell AMC8? Beginning at the A in the middle, a path allows only moves from one letter to an adjacent (above, below, left, or right, but not diagonal) letter. One example of such a path is traced in the picture.

(A) 8
(B) 9
(C) 12
(D) 24
(E) 36

ANSWER : (D) 24

PROBLEM 16 :

In the figure below, choose point $D$ on $\overline{B C}$ so that $\triangle A C D$ and $\triangle A B D$ have equal perimeters. What is the area of $\triangle A B D$ ?

(A) $\frac{3}{4}$
(B) $\frac{3}{2}$
(C) 2
(D) $\frac{12}{5}$
(E) $\frac{5}{2}$

ANSWER : (D) $\frac{12}{5}$

PROBLEM 17 :

Starting with some gold coins and some empty treasure chests, I tried to put 9 gold coins in each treasure chest, but that left 2 treasure chests empty. So instead I put 6 gold coins in each treasure chest, but then I had 3 gold coins left over. How many gold coins did I have?
(A) 9
(B) 27
(C) 45
(D) 63
(E) 81

ANSWER : (C) 45

PROBLEM 18 :

In the non-convex quadrilateral $A B C D$ shown below, $\angle B C D$ is a right angle, $A B=12, B C=4, C D=3$, and $A D=13$.

What is the area of quadrilateral $A B C D$ ?
(A) 12
(B) 24
(C) 26
(D) 30
(E) 36

ANSWER : (B) 24

PROBLEM 19 :

For any positive integer $M$, the notation $M!$ denotes the product of the integers 1 through $M$. What is the largest integer $n$ for which $5^n$ is a factor of the sum $98!+99!+100!$ ?
(A) 23
(B) 24
(C) 25
(D) 26
(E) 27

ANSWER : (D) 26

PROBLEM 20 :

An integer between 1000 and 9999 , inclusive, is chosen at random. What is the probability that it is an odd integer whose digits are all distinct?
(A) $\frac{14}{75}$
(B) $\frac{56}{225}$
(C) $\frac{107}{400}$
(D) $\frac{7}{25}$
(E) $\frac{9}{25}$

ANSWER : (B) $\frac{56}{225}$

PROBLEM 21 :

Suppose $a, b$, and are nonzero real numbers, and . What are the possible value(s) for $\frac{a}{|a|}+\frac{b}{|b|}+\frac{c}{|c|}+\frac{a b c}{|a b c|}$ ?
(A) 0
(B) 1 and - 1
(C) 2 and - 2
(D) 0,2, and - 2
(E) 0 , 1 , and -1

ANSWER : (A) 0

PROBLEM 22 :

In the right triangle $A B C, A C=12, B C=5$, and angle $C$ is a right angle. A semicircle is inscribed in the triangle as shown. What is the radius of the semicircle?

(A) $\frac{7}{6}$
(B) $\frac{13}{5}$
(C) $\frac{59}{18}$
(D) $\frac{10}{3}$
(E) $\frac{60}{13}$

ANSWER : (D) $\frac{10}{3}$

PROBLEM 23 :

Each day for four days, Linda traveled for one hour at a speed that resulted in her traveling one mile in an integer number of minutes. Each day after the first, her speed decreased so that the number of minutes to travel one mile increased by 5 minutes over the preceding day. Each of the four days, her distance traveled was also an integer number of miles. What was the total number of miles for the four trips?
(A) 10
(B) 15
(C) 25
(D) 50
(E) 82

ANSWER : (C) 25

PROBLEM 24 :

Mrs. Sanders has three grandchildren, who call her regularly. One calls her every three days, one calls her every four days, and one calls her every five days. All three called her on December 31, 2021. On how many days during the next year did she not receive a phone call from any of her grandchildren?
(A) 78
(B) 80
(C) 144
(D) 146
(E) 152

ANSWER : (D) 146

PROBLEM 25 :

In the figure shown, $\overline{U S}$ and $\overline{U T}$ are line segments each of length 2 , and $m \angle T U S=60^{\circ}$. Arcs $\overparen{\mathrm{TR}}$ and $\overparen{\mathrm{SR}}$ are each one-sixth of a circle with radius 2 . What is the area of the region shown?

ANSWER : (B)

AMERICAN MATHEMATICS COMPETITION - 2020


Problem 1 :
Luka is making lemonade to sell at a school fundraiser. His recipe requires 4 times as much water as sugar and twice as much sugar as lemon juice. He uses 3 cups of lemon juice. How many cups of water does he need?
(A) 6
(B) 8
(C) 12
(D) 18
(E) 24

ANSWER :

(E) 24

Problem 2 :
Four friends do yardwork for their neighbors over the weekend, earning $\$ 15, \$ 20, \$ 25$, and $\$ 40$, respectively. They decide to split their earnings equally among themselves. In total how much will the friend who earned $\$ 40$ give to the others?
(A) $\$ 5$
(B) $\$ 10$
(C) $\$ 15$
(D) $\$ 20$
(E) $\$ 25$

ANSWER :

(C) $\$ 15$

Problem 3 :
Carrie has a rectangular garden that measures 6 feet by 8 feet. She plants the entire garden with strawberry plants. Carrie is able to plant 4 strawberry plants per square foot, and she harvests an average of 10 strawberries per plant. How many strawberries can she expect to harvest?
(A) 560
(B) 960
(C) 1120
(D) 1920
(E) 3840

ANSWER :

(D) 1920

Problem 4 :
Three hexagons of increasing size are shown below. Suppose the dot pattern continues so that each successive hexagon contains one more band of dots. How many dots are in the next hexagon?


(A) 35
(B) 37
(C) 39
(D) 43
(E) 49

ANSWER :

(B) 37

Problem 5 :
Three fourths of a pitcher is filled with pineapple juice. The pitcher is emptied by pouring an equal amount of juice into each of 5 cups. What percent of the total capacity of the pitcher did each cup receive?
(A) 5
(B) 10
(C) 15
(D) 20
(E) 25

ANSWER :

(C) 15

Problem 6 :
Aaron, Darren, Karen, Maren, and Sharon rode on a small train that has five cars that seat one person each. Maren sat in the last car. Aaron sat directly behind Sharon. Darren sat in one of the cars in front of Aaron. At least one person sat between Karen and Darren. Who sat in the middle car?
(A) Aaron
(B) Darren
(C) Karen
(D) Maren
(E) Sharon

ANSWER :

(A) Aaron

Problem 7 :
How many integers between 2020 and 2400 have four distinct digits arranged in increasing order? (For example, 2357 is one such integer.)
(A) 9
(B) 10
(C) 15
(D) 21
(E) 28

ANSWER :

(C) 15

Problem 8 :

Ricardo has 2020 coins, some of which are pennies (1-cent coins) and the rest of which are nickels (5-cent coins). He has at least one penny and at least one nickel. What is the difference in cents between the greatest possible and least possible amounts of money that Ricardo can have?
(A) 8062
(B) 8068
(C) 8072
(D) 8076
(E) 8082

ANSWER :

(C) 8072

Problem 9 :
Akash's birthday cake is in the form of a $4 \times 4 \times 4$ inch cube. The cake has icing on the top and the four side faces, and no icing on the bottom. Suppose the cake is cut into 64 smaller cubes, each measuring $1 \times 1 \times 1$ inch, as shown below. How many of the small pieces will have icing on exactly two sides?


(A) 12
(B) 16
(C) 18
(D) 20
(E) 24

ANSWER :

(D) 20

Problem 10 :
Zara has a collection of 4 marbles: an Aggie, a Bumblebee, a Steelie, and a Tiger. She wants to display them in a row on a shelf, but does not want to put the Steelie and the Tiger next to one another. In how many ways can she do this?
(A) 6
(B) 8
(C) 12
(D) 18
(E) 24

ANSWER :

(C) 12

Problem 11 :
After school, Maya and Naomi headed to the beach, 6 miles away. Maya decided to bike while Naomi took a bus. The graph below shows their journeys, indicating the time and distance traveled. What was the difference, in miles per hour, between Naomi's and Maya's average speeds?


(A) 6
(B) 12
(C) 18
(D) 20
(E) 24

ANSWER :

(E) 24

Problem 12 :
For positive integer $n$, the factorial notation $n!$ represents the product of the integers from $n$ to 1 . (For example, $6!=6 \cdot 5 \cdot 4 \cdot 3 \cdot 2 \cdot 1$.) What value of $N$ satisfies the following equation?

$$
5!\cdot 9!=12 \cdot N!
$$

(A) 10
(B) 11
(C) 12
(D) 13
(E) 14

ANSWER :

(A) 10

Problem 13 :
Jamal has a drawer containing 6 green socks, 18 purple socks, and 12 orange socks. After adding more purple socks, Jamal noticed that there is now a $60 \%$ chance that a sock randomly selected from the drawer is purple. How many purple socks did Jamal add?
(A) 6
(B) 9
(C) 12
(D) 18
(E) 24

ANSWER :

(B) 9

Problem 14 :
There are 20 cities in the County of Newton. Their populations are shown in the bar chart below. The average population of all the cities is indicated by the horizontal dashed line. Which of the following is closest to the total population of all 20 cities?


(A) 65,000
(B) 75,000
(C) 85,000
(D) 95,000
(E) 105,000

ANSWER :

(D) 95,000

Problem 15 :
Suppose $15 \%$ of $x$ equals $20 \%$ of $y$. What percentage of $x$ is $y$ ?


(A) 5
(B) 35
(C) 75
(D) $133 \frac{1}{3}$
(E) 300

ANSWER :

(C) 75

Problem 16 :
Each of the points $A, B, C, D, E$, and $F$ in the figure below represents a different digit from 1 to 6 . Each of the five lines shown passes through some of these points. The digits along each line are added to produce five sums, one for each line. The total of the five sums is 47 . What is the digit represented by $B$ ?


(A) 1
(B) 2
(C) 3
(D) 4
(E) 5

ANSWER :

(E) 5

Problem 17 :
How many factors of 2020 have more than 3 factors? (As an example, 12 has 6 factors, namely 1 , $2,3,4,6$, and 12 .)
(A) 6
(B) 7
(C) 8
(D) 9
(E) 10

ANSWER :

(B) 7

Problem 18 :
Rectangle $A B C D$ is inscribed in a semicircle with diameter $\overline{F E}$, as shown in the figure. Let $D A=$ 16, and let $F D=A E=9$. What is the area of $A B C D$ ?


(A) 240
(B) 248
(C) 256
(D) 264
(E) 272

ANSWER :

(A) 240

Problem 19 :
A number is called flippy if its digits alternate between two distinct digits. For example, 2020 and 37373 are flippy, but 3883 and 123123 are not. How many five-digit flippy numbers are divisible by 15 ?
(A) 3
(B) 4
(C) 5
(D) 6
(E) 8

ANSWER :

(B) 4

Problem 20 :
A scientist walking through a forest recorded as integers the heights of 5 trees standing in a row. She observed that each tree was either twice as tall or half as tall as the one to its right. Unfortunately some of her data was lost when rain fell on her notebook. Her notes are shown below, with blanks indicating the missing numbers. Based on her observations, the scientist was able to reconstruct the lost data. What was the average height of the trees, in meters?

(A) 22.2
(B) 24.2
(C) 33.2
(D) 35.2
(E) 37.2

ANSWER :

(B) 24.2

Problem 21 :
A game board consists of 64 squares that alternate in color between black and white. The figure below shows square $P$ in the bottom row and square $Q$ in the top row. A marker is placed at $P$. A step consists of moving the marker onto one of the adjoining white squares in the row above. How many 7 -step paths are there from $P$ to $Q$ ? (The figure shows a sample path.)


(A) 28
(B) 30
(C) 32
(D) 33
(E) 35

ANSWER :

(A) 28

Problem 22 :
When a positive integer $N$ is fed into a machine, the output is a number calculated according to the rule shown below.

For example, starting with an input of $N=7$, the machine will output $3 \cdot 7+1=22$. Then if the output is repeatedly inserted into the machine five more times, the final output is 26 .

$$
7 \rightarrow 22 \rightarrow 11 \rightarrow 34 \rightarrow 17 \rightarrow 52 \rightarrow 26
$$

When the same 6 -step process is applied to a different starting value of $N$, the final output is 1 . What is the sum of all such integers $N$ ?

$$
N \rightarrow {-} \rightarrow {-} \rightarrow \rightarrow {-} \rightarrow {-} \rightarrow 1
$$

(A) 73
(B) 74
(C) 75
(D) 82
(E) 83

ANSWER :

(E) 83

Problem 23 :
Five different awards are to be given to three students. Each student will receive at least one award. In how many different ways can the awards be distributed?
(A) 120
(B) 150
(C) 180
(D) 210
(E) 240

ANSWER :

(B) 150

Problem 24 :
A large square region is paved with $n^{2}$ gray square tiles, each measuring $s$ inches on a side. A border $d$ inches wide surrounds each tile. The figure below shows the case for $n=3$. When $n=$ 24 , the 576 gray tiles cover $64 \%$ of the area of the large square region. What is the ratio $\frac{d}{s}$ for this larger value of $n$ ?


(A) $\frac{6}{25}$
(B) $\frac{1}{4}$
(C) $\frac{9}{25}$
(D) $\frac{7}{16}$
(E) $\frac{9}{16}$

ANSWER :

(A) $\frac{6}{25}$

Problem 25 :
Rectangles $R_{1}$ and $R_{2}$, and squares $S_{1}, S_{2}$, and $S_{3}$, shown below, combine to form a rectangle that is 3322 units wide and 2020 units high. What is the side length of $S_{2}$ in units?


(A) 651
(B) 655
(C) 656
(D) 662
(E) 666

ANSWER :

(A) 651

American Mathematics Competition - 2019

Question 1 :

Ike and Mike go into a sandwich shop with a total of $\$ 30.00$ to spend. Sandwiches cost $\$ 4.50$ each and soft drinks cost $\$ 1.00$ each. Ike and Mike plan to buy as many sandwiches as they can, and use any remaining money to buy soft drinks. Counting both sandwiches and soft drinks, how many items will they buy?
(A) 6
(B) 7
(C) 8
(D) 9
(E) 10

Answer 1 :

(D) 9

Question 2:

Three identical rectangles are put together to form rectangle $A B C D$, as shown in the figure below. Given that the length of the shorter side of each of the smaller rectangles is 5 feet, what is the area in square feet of rectangle $A B C D$ ?

(A) 45
(B) 75
(C) 100
(D) 125
(E) 150

Answer 2 :

(E) 150

Question 3 :

Which of the following is the correct order of the fractions $\frac{15}{11}, \frac{19}{15}$, and $\frac{17}{13}$, from least to greatest?
(A) $\frac{15}{11}<\frac{17}{13}<\frac{19}{15}$
(B) $\frac{15}{11}<\frac{19}{15}<\frac{17}{13}$
(C) $\frac{17}{13}<\frac{19}{15}<\frac{15}{11}$
(D) $\frac{19}{15}<\frac{15}{11}<\frac{17}{13}$
(E) $\frac{19}{15}<\frac{17}{13}<\frac{15}{11}$

Answer 3 :

(E) $\frac{19}{15}<\frac{17}{13}<\frac{15}{11}$

Question 4 :

Quadrilateral $A B C D$ is a rhombus with perimeter 52 meters. The length of diagonal $\overline{A C}$ is 24 meters. What is the area in square meters of rhombus $A B C D$ ?

(A) 60
(B) 90
(C) 105
(D) 120
(E) 144

Answer 4 :

(D) 120

Question 5 :

A tortoise challenges a hare to a race. The hare eagerly agrees and quickly runs ahead, leaving the slow-moving tortoise behind. Confident that he will win, the hare stops to take a nap. Meanwhile, the tortoise walks at a slow steady pace for the entire race. The hare awakes and runs to the finish line, only to find the tortoise already there. Which of the following graphs matches the description of the race, showing the distance $d$ traveled by the two animals over time $l$ from start to finish?

Answer 5 :

Question 6 :

There are 81 grid points (uniformly spaced) in the square shown in the diagram below, including the points on the edges. Point $P$ is in the center of the square. Given that point $Q$ is randomly chosen among the other 80 points, what is the probability that the line $P Q$ is a line of symmetry for the square?

(A) $\frac{1}{5}$
(B) $\frac{1}{4}$
(C) $\frac{2}{5}$
(D) $\frac{9}{20}$
(E) $\frac{1}{2}$

Answer 6 :

(C) $\frac{2}{5}$

Question 7 :

Shauna takes five tests, each worth a maximum of 100 points. Her scores on the first three tests are 76,94 , and 87 . In order to average 81 for all five tests, what is the lowest score she could earn on one of the other two tests?
(A) 48
(B) 52
(C) 66
(D) 70
(E) 74

Answer 7 :

(A) 48

Question 8 :

Gilda has a bag of marbles. She gives $20 \%$ of them to her friend Pedro. Then Gilda gives $10 \%$ of what is left to another friend, Ebony. Finally, Gilda gives $25 \%$ of what is now left in the bag to her brother Jimmy. What percentage of her original bag of marbles does Gilda have left for herself?
(A) 20
(B) $33 \frac{1}{3}$
(C) 38
(D) 45
(E) 54

Answer 8 :

(E) 54

Question 9 :

Alex and Felicia each have cats as pets. Alex buys cat food in cylindrical cans that are 6 cm in diameter and 12 cm high. Felicia buys cat food in cylindrical cans that are 12 cm in diameter and 6 cm high. What is the ratio of the volume of one of Alex's cans to the volume of one of Felicia's cans?
(A) $1: 4$
(B) $1: 2$
(C) $1: 1$
(D) $2: 1$
(E) $4: 1$

Answer 9 :

(B) $1: 2$

Question 10 :

The diagram shows the number of students at soccer practice each weekday during last week. After computing the mean and median values, Coach discovers that there were actually 21 participants on Wednesday. Which of the following statements describes the change in the mean and median after the correction is made?

(A)The mean increases by 1 and the median does not change.
(B)The mean increases by 1 and the median increases by 1 .
(C) The mean increases by 1 and the median increases by 5 .
(D)The mean increases by 5 and the median increases by 1 .
(E)The mean increase by 5 and the median increases by 5 .

Answer 10 :

(B)The mean increases by 1 and the median increases by 1 .

Question 11 :

The eighth grade class at Lincoln Middle School has 93 students. Each student takes a math class or a foreign language class or both. There are 70 eighth graders taking a math class, and there are 54 eighth graders taking a foreign language class. How many eighth graders take only a math class and not a foreign language class?
(A) 16
(B) 53
(C) 31
(D) 39
(E) 70

Answer 11 :

(D) 39

Question 12 :

The faces of a cube are painted in six different colors: red $(R)$, white $(W)$, green $(G)$, brown $(B)$, aqua $(A)$, and purple $(P)$. Three views of the cube are shown below. What is the color of the face opposite the aqua face?

Answer 12 :

(A) R

Question 13 :

A palindrome is a number that has the same value when read from left to right or from right to left. (For example, 12321 is a palindrome.) Let $N$ be the least three-digit integer which is not a palindrome but which is the sum of three distinct two-digit palindromes. What is the sum of the digits of $N$ ?
(A) 2
(B) 3
(C) 4
(D) 5
(E) 6

Answer 13 :

(A) 2

Question 14 :

Isabella has 6 coupons that can be redeemed for free ice cream cones at Pete's Sweet Treats. In order to make the coupons last, she decides that she will redeem one every 10 days until she has used them all. She knows that Pete's is closed on Sundays, but as she circles the 6 dates on her calendar, she realizes that no circled date falls on a Sunday. On what day of the week does Isabella redeem her first coupon?
(A) Monday
(B) Tuesday
(C) Wednesday
(D) Thursday
(E) Friday

Answer 14 :

(C) Wednesday

Question 15 :

On a beach 50 people are wearing sunglasses and 35 people are wearing caps. Some people are wearing both sunglasses and caps. If one of the people wearing a cap is selected at random, the probability that this person is also wearing sunglasses is $\frac{2}{5}$. If instead, someone wearing sunglasses is selected at random, what is the probability that this person is also wearing a cap?
(A) $\frac{14}{85}$
(B) $\frac{7}{25}$
(C) $\frac{2}{5}$
(D) $\frac{4}{7}$
(E) $\frac{7}{10}$

Answer 15 :

(B) $\frac{7}{25}$

Question 16 :

Qiang drives 15 miles at an average speed of 30 miles per hour. How many additional miles will he have to drive at 55 miles per hour to average 50 miles per hour for the entire trip?
(A) 45
(B) 62
(C) 90
(D) 110
(E) 135

Answer 16 :

(D) 110

Question 17 :

What is the value of the product

$$
\left(\frac{1 \cdot 3}{2 \cdot 2}\right)\left(\frac{2 \cdot 4}{3 \cdot 3}\right)\left(\frac{3 \cdot 5}{4 \cdot 4}\right) \cdots\left(\frac{97 \cdot 99}{98 \cdot 98}\right)\left(\frac{98 \cdot 100}{99 \cdot 99}\right) ?
$$

(A) $\frac{1}{2}$
(B) $\frac{50}{99}$
(C) $\frac{9800}{9801}$
(D) $\frac{100}{99}$
(E) 50

Answer 17 :

(B) $\frac{50}{99}$

Question 18 :

The faces of each of two fair dice are numbered $1,2,3,5,7$, and 8 . When the two dice are tossed, what is the probability that their sum will be an even number?
(A) $\frac{4}{9}$
(B) $\frac{1}{2}$
(C) $\frac{5}{9}$
(D) $\frac{3}{5}$
(E) $\frac{2}{3}$

Answer 18 :

(C) $\frac{5}{9}$

Question 19 :

In a tournament there are six teams that play each other twice. A team earns 3 points for a win, 1 point for a draw, and 0 points for a loss. After all the games have been played it turns out that the top three teams earned the same number of total points. What is the greatest possible number of total points for each of the top three teams?
(A) 22
(B) 23
(C) 24
(D) 26
(E) 30

Answer 19 :

(C) 24

Question 20 :

How many different real numbers $x$ satisfy the equation

$$
\left(x^2-5\right)^2=16 ?
$$

(A) 0
(B) 1
(C) 2
(D) 4
(E) 8

Answer 20 :

(D) 4

Question 21 :

What is the area of the triangle formed by the lines $y=5, y=1+x$, and $y=1-x$ ?
(A) 4
(B) 8
(C) 10
(D) 12
(E) 16

Answer 21 :

(E) 16

Question 22 :

A store increased the original price of a shirt by a certain percent and then lowered the new price by the same amount. Given that the resulting price was $84 \%$ of the original price, by what percent was the price increased and decreased?
(A) 16
(B) 20
(C) 28
(D) 36
(E) 40

Answer 22 :

(E) 40

Question 23 :

After Euclid High School's last basketball game, it was determined that $\frac{1}{4}$ of the team's points were scored by Alexa and $\frac{2}{7}$ were scored by Brittany. Chelsea scored 15 points. None of the other 7 team members scored more than 2 points. What was the total number of points scored by the other 7 team members?
(A) 10
(B) 11
(C) 12
(D) 13
(E) 14

Answer 23 :

(B) 11

Question 24 :

In triangle $\triangle A B C$, point $D$ divides side $\overline{A C}$ so that $A D: D C=1: 2$. Let $E$ be the midpoint of $\overline{B D}$ and let $F$ be the point of intersection of line $\overline{B C}$ and line $\overline{A E}$. Given that the area of $\triangle A B C$ is 360, what is the area of $\triangle E B F$ ?

(A) 24
(B) 30
(C) 32
(D) 36
(E) 40

Answer 24 :

(B) 30

Question 25 :

Alice has 24 apples. In how many ways can she share them with Becky and Chris so that each of the three people has at least two apples?
(A) 105
(B) 114
(C) 190
(D) 210
(E) 380

Answer 25 :

(C) 190