A number when divided by 7 leaves a remainder of 3. What will be the remainder when the square of the number is divided by 7?
Q1. A number when divided by 7 leaves a remainder of 3. What will be the remainder when the square of the number is divided by 7?
Answer: 2
Explanation: Let N = 7k + 3. N² = (7k + 3)² = 49k² + 42k + 9 = 7(7k² + 6k + 1) + 2. So, remainder = 2.