1. The problem statement, all variables and given/known data A finite,commutative grp is not cyclic iff it has a subgrp that is isomorphic to (Z mod p) x (Z mod p) , for a prime p. 2. Relevant equations I am having trouble and I would appreciate a hint. 3. The attempt at a solution Let G be a finite commutative grp with order n. Assume that G is not cyclic. This means that there are no elements in G which are relatively prime with n and n is not a prime otherwise it would be cyclic.