Question

show that 15 power n can't end with digit 0 for natural number

Answer 1

BEFORE USING PRINCIPLES OF MATHEMATICAL INDUCTION ...
WE CAN HERE CONCLUDE THE THEORY OF NUMBERS ...
WHICH DESCRIBES THE SWITCH NUMBERS SYSTEMS ...
HERE , 15ⁿ HAS PERIOD OF UNITY AND SWITCH NUMBER IS 5 RESPECTIVELY ...
WHICH STATES THAT ... FOR EVERY POSITIVE INTEGER "n" THERE WILL BE THE VALUE OF GIVEN EXPRESSION ENDING WITH 5 ALWAYS ...

HENCE , IT CAN NEVER END WITH 0