firstly, we can get 3^15=== 7 (mod100) =>3^990 ===7^66
Now,7^4=== 1(mod 100) =>7^66 === 1*7^2 = 49
and, 3^9=== 83 (mod100)
So, 3^999 = 3^990 *3^9=== 49*83 = 4067 === 67
Rightmost two digits of 3^999 is 7 and 6
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- Thu Jan 04, 2018 12:59 am
- Forum: Higher Secondary Level
- Topic: Rightmost two digits of 3^999
- Replies: 5
- Views: 8153