71= 07 72= 49 73= 343 74= 2401 75= 16807 76= 117649 77= 823543 78= 5764801 Here, note that the last twodigitsof 74and 78are 01. For every 4th power, the last digits are 01 Since 2008 is divisible by 4, the last digits of72008are 01. THanks
Bharat Bajaj IIT Delhi
askiitians faculty
Manas Satish Bedmutha
Last Activity: 11 Years ago
7 = 07 (mod 100)
7 ^ 2 = 49 (mod 100)
7 ^ 4 = 01 (mod 100)
So 7 ^ (4 x 502) = 7 ^ 2008 = 01 (mod 100)
Hence last 2 digits are 01
LIVE ONLINE CLASSES
Prepraring for the competition made easy just by live online class.