What is Remainder?
A remainder in mathematics is what’s left over in a division problem. In the division process, the number we want to divide up is known as the dividend, while the number we are dividing by is referred to as the divisor; the result is the quotient. Let’s solve a problem based on divisibility and remainder.
Try the problem from Mathematical Circles – Divisibility and Remainder – Problem 16
Prove that the number $(n^3+2\times n)$ is divisible by 3 for a natural number $n$.
Divisibility and Remainder
4 out of 10
Use some hints
the number $n$ can give any of the following remainders 0,1 or 2 when divided by 3.
if $n$ has remainder 0, therefore $n^3$ and $2n$ both are divisible by 3. Hence it is proved.