Sheridan Shacks makes portable garden sheds that sell for $$\$ 1,800$$ each. Costs are as follows:
$$
\begin{array}{lcc}
& \text { Per Unit } & \text { Total } \\
\hline \text { Direct material } & \$ 800 & \\
\text { Direct labor } & 90 & \\
\text { Variable production overhead } & 60 & \\
\text { Variable selling and administrative cost } & 50 & \\
\text { Fixed production overhead } & & \$ 200,000 \\
\text { Fixed selling and administrative } & & 60,000
\end{array}
$$
a. How many garden sheds must the company sell to break even?
b. If Sheridan Shacks' management wants to earn a pre-tax profit of $$\$ 200,000$$, how many garden sheds must it sell?
c. If Sheridan Shacks' management wants to earn a pre-tax profit of $$\$ 280,000$$, how many garden sheds must it sell?