check whether 15^n can end with digit zero for any natural number n

15^n = (3 x 5)^n

  =  3^n x 5^n

The prime factorization of 15 doesn't have a 2 and 5 as its factor. So, its factorization will never end in 10 as a number ending in 10 must have a factors as 5 and 2. So, 15^n will never end in zero as 15 doesn't has 2 as a factor.

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