The Following Monthly Budgeted Data Are Available for the International

The following monthly budgeted data are available for the International Company:
$\begin{array}{|l|r|r|r|}\hline & \text { Product A } & \text { Product B } & \text { Product C } \\\hline \text { Sales } & \$ 500,000 & \$ 300,000 & \$ 900,000 \\\hline \text { Variable expenses } & \underline{300,000} & 210,000 & \underline{720,000} \\\hline \text { Contribution margin } & \$ 200,000 & \$ 90,000 & \$ 180,000 \\\hline\end{array}$
Budgeted operating income for the month is $220,000.
Required:
a)Calculate the break-even sales for the month.
b)Calculate the margin of safety.
c)Calculate the degree of operating leverage.