What is the last digit of 6109?
3
8
6
4
Consider, 61=6, last digit is 6. 62=36, last digit is 6.
63=216, last digit is 6.
64=1296, last digit is 6.
On generalizing, we get last digit in 6109 as 6.
What is the last digit of 2100?
What is the last digit of 109?