If $|G| = n < 60$, and $n$ is composite, then $G$ is not a simple group. I am not totally sure how to solve this.
So far, I have tried thinking of every possible theorem I can think of.
A simple group is one where the only normal subgroups are trivial. If $G$ is group of prime order, then it must be a simple group since its only factors are $1$ and the prime order.
In this case, factors of $60 = 2^{2} \times 3 \times5 $. Now, according to Sylow's first theorem, it must contain $p$-groups of order of $4, 3$ and $5$.
And according to Lagrange's theorem, its subgroups must have order $1, 2, 3, 4, 5, 6, 10, 12, 15$.
I am not really sure how to proceed from here to show that indeed, the group cannot be a simple group. Any help would be greatly appreciated?