Question

give me a solution:
find the last two digit of
${3}^{1997}$

Answer 1

answer is 63

unit digit of power of any number ending with 1 is always 1.

2nd digit is always obtained by multiplying digit on the left of 1 and last digit of power.
here it is 8 X 9 =72 that means 2. so 21 are last two digits of (81)power 499.

final answer is 21x3 = 63.