Hi all, I was wondering if any maths people could help me with a question that I am stuck at that is really bothering me. [See picture below]. I know the order of the set S15 is 15! (15 factorial). I also know how to prove the set H is a supgroup of S15. Can anyone tell me though, what the order of the subgroup is? Is it the same as the order of the set S15? Any help would be greatly appreciated.