Question
1997^913 when it is divided by 10 what is the remainder???
Answers
Steve
all you want is the last digit. So, look at the powers of 7:
7^1 = 7
7^2 = 49
7^3 ends in 3
7^4 ends in 1 since 3*7=21
913 = 4*228 + 1
So, 7^913 = 7^4^228 * 7
thus, it ends in 7
7^1 = 7
7^2 = 49
7^3 ends in 3
7^4 ends in 1 since 3*7=21
913 = 4*228 + 1
So, 7^913 = 7^4^228 * 7
thus, it ends in 7