Prove that $S_5$ has no elements of order $120$.
I know that by Lagrange's theorem, elements can have order $1, 2, 3, 4, 5, 6, 8, 10, 12, 15, 20, 24, 30, 40, 60, 120$.
I feel like I need to use some sort of contradiction argument here but I'm not sure where to go with that. Any suggestions?