Find the ones digit of 73^320 Choose the most appropriate option
A) 3
B) 5
C) 6
D) 7
E) 9
Cyclicity of 3 is 3,9,7,1after 4 multiplication again the cycle repeats.   So divide 320 by 4 and we get 87 as quotient and 2 as remainder. So cycle will run for 87 times and then 2 times more. So pick up the 2nd item from the cycle.   Hence Answer 7.
<result>D</result>
Find the ones digit of 73^320