Unitary ratios

The moon takes 328 days to orbit earth 12 times.

How many times will it orbit earth in 246 days

$\begin{array}{|rcll|} \hline \dfrac{12\ \text{Orbits} }{328\ \text{days}} \cdot 246\ \text{days} = 9 \ \text{Orbits} \\ \hline \end{array}$