Question

Find the last three digits of 87²⁰⁰²​

Answer 1

Cyclicity of 7 is 4

Which means that if we multiply 7 for 4 times the unit digit of the obtained no. will be 7.

7^1 = 7

7^2 = 49

In the above question ;

87^2002

Which Means that the last digit of the above no. is

9.