## Find the amount of subgroups of order \$3\$ and \$21\$ in non-cyclic abelian group of order \$63\$

Find the amount of subgroups of order $$3$$ and $$21$$ in non-cyclic abelian group of order $$63$$.

In first case I found the amount of elements that have order $$3$$ – there are $$8$$ of them, in second case there are $$48$$ elements of order $$21$$. How do I connect these values with the amount of subgroups now?