(Q1).Can the number 6n , n being a natural number, end with the digit 5? Give reason

Here we've 6n

6n = (2 × 3)n

6n = (2 × 3)n

6n = (2 × 3)n = 2n × 3n ,

Here 6n = (2 × 3)n = 2n × 3n ,

and are the only primes in the factorization of 6n, and not 5.

Therefore, it cannot end with the digit