Sunday, June 9, 2019

elementary number theory - Find the remainder when $787^{777}$ is divided by $100$?


Find the remainder when $787^{777}$ is divided by $100$?




MyApproach




$787^{20\times38+17}$=$787^{17}$=I will get the last digit of remainder as 7 but how to calculate tens digit in this question fast using this approach only.




Similarly,Find the remainder when $948^{728}$ is divided by $100$.




On solving I get $948^8$=I will get the last digit of remainder as 7 but how to calculate tens digit in this question fast using this approach only.



Again here how to calculate the other digits fast.

No comments:

Post a Comment

analysis - Injection, making bijection

I have injection $f \colon A \rightarrow B$ and I want to get bijection. Can I just resting codomain to $f(A)$? I know that every function i...