## Powerful Divisibility

#### Problem

Given that `n` is a positive integer, prove that 21^{n} 5^{n} + 8^{n} is always divisible by 24.

Problem ID: 32 (Jan 2001) Difficulty: 3 Star

Given that `n` is a positive integer, prove that 21^{n} 5^{n} + 8^{n} is always divisible by 24.

Problem ID: 32 (Jan 2001) Difficulty: 3 Star