Well you know it should be isomorphic to a subgroup of and it needs to be cyclic, so you need only find an element of which has order 5. (1 2 3 4 5) is a good choice, the isomorphism is as follows:
Can someone help me with the following problem?
Let G be the cyclic group <a> of order 5.
1. Write out the elements of a group of permutations that is isomorphic to G.
2. Exhibit an isomorphism from G to this group.