Normal Subgroups and Quotient Groups · Medium problem

In $\mathbb Z_{60}$, let $H = \langle 6\rangle$ (order $10$) and $N = \langle 10\rangle$ (order $6$). Using the Second Isomorphism Theorem relation $|HN| = \dfrac{|H||N|}{|H\cap N|}$, what is $|HN|$?