5. Check whether 6^n can end with the digit 0 for any natural number n.

5. Check whether 6n can end with the digit 0 for any natural number n.

A number ends with digit 0 if it is divisible by 10.

10 = 2 × 5

6n = (2 × 3)n

Thus, 6n contains only the prime factors 2 and 3 and does not contain factor 5.

Therefore, 6n cannot be divisible by 10.

Hence, 6n cannot end with the digit 0 for any natural number n.