Question

Consider S={0,1,2} is the set of residue classes modulo 3 under addition then inverse of 2 is???

Answer 1

The inverse of 2 under addition modulo 3 is 1.

Explanation:

The inverse `a^-1`of an element `a` is defined such that `a+a^-1=e` where `e` is the identity element and `+` is the group operator. Since `2+1-=0 (mod3)` and `0` is the identity element in `ZZ"/"3ZZ`, the inverse of 2 is 1 in `ZZ"/"3ZZ`.