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.