Question

Show that 12 raise to n cannot end with the digit 0 or 5 for any natural number n

Answer 1

Here, Number=12^n where n stand for any natural number .

Now 12^n= (2^2 x3)^n

Now , For 12^n to end with 0, it should have 2 as well as 5 in its Prime factors to end with 0, Also to end with 5 , it requires at least a single multiple of 5 in its Prime Factors, So 12^ncannot end with the digit 0 or 5.

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