We can solve this using ratios :
$$60\ min : 1\ hr \rightarrow x : m\ hr $$
or
$$ \dfrac{60\ min}{1\ hr} = \dfrac{x}{m\ hr} $$
$$ mhr \cdot \dfrac{60\ min}{1\ hr} = mhr \cdot \dfrac{x}{mhr} $$
$$ m\ hr \cdot \dfrac{60\ min}{1\ hr} = m\ hr \cdot \dfrac{x}{m\ hr} $$
$$60\ m $$ minutes = $$x$$
Therefore there are $$60\ m $$ minutes in $$m$$ hours.