what is the remainder when 12987 ^ ( 65987036 ) is divided by 5 ?
"we need to find the units digit of the number . the units digit of powers of seven repeats 7 , 9 , 3 , and 1 cyclically . since 65987036 has the form 4 a , the units digit is 1 . then the remainder when dividing by 5 is 1 . the answer is b ."
reminder(multiply(65987036, 12987), 5)