Sign Pyramid – AMC 8 2018 Problem 19

Sign Pyramid – AMC 8 2018 Problem 19

Big idea – stabilization In a counting problem, you may need to stabilize the number of cases. This means, by letting some of the variables change, one may fix the remaining cases. This is the central idea in the following problem from American Mathematical...
AMC 10 Paper Folding Geometry

AMC 10 Paper Folding Geometry

We fold a paper using GeoGebra and explore a problem from American Mathematical Contest (AMC 10) Problem: A rectangular piece of paper whose length is \( \sqrt 3 \) times the width has area A. The paper is divided into three equal sections along the opposite lengths,...
UCLA full scholarship program – MUMS

UCLA full scholarship program – MUMS

Cheenta Opportunity is an initiative for the benefit of Cheenta Olympiad candidates. We dig up opportunities and resources available all around the world for our students.  University of  California, Los Angles is one of the leading universities in the world. Its...
AMC 10A 2016

AMC 10A 2016

What is the value of \( \dfrac{11!-10!}{9!}\)? (A) 99 (B) 100 (C) 110 (D) 121 (E) 132 For what value of \( x \) does \( 10^x \cdot 100^{2x} = 1000^5 \)? (A) 1 (B) 2 (C) 3 (D) 4 (E) 5 For every dollar Ben spent on bagels, David spent 25 cents less. Ben paid $12.50 more...
Beautiful Books

Beautiful Books

This is an (ever-growing and ever-changing) list of books, useful for school and college mathematics students. If you are working toward Math Olympiad, I.S.I., C.M.I. entrance programs or intense college mathematics, these books may prove to be your best friend. If...