Question

Show that 12n cannot end with the digits 0 or 5 for any natural numbenumber

Answer 1

Let 12n ends with 0 or 5. But, if it ends with 0 or 5, it should only 2 and 5 as it's prime factors. But, if we see the primer factorisation if 12 it also has 3 as one of it's prime factors. So, our assumption is wrong.

Hence, it cannot end with 0 it 5.

Hope it helps!!!