A number leaves a remainder of 5 when divided by 7. What is the remainder when the square of the number is divided by 7?

Explanation

1. 01

   The remainder of a product is the product of the remainders, reduced by the divisor.

2. 02

   Square of the remainder: $5^2 = 25$.

3. 03

   $25 = 7 \times 3 + 4$, so the remainder is 4.