Fort Smith Technologies incurred the following costs during the past year when planned production and actual production each totaled $20,000$ units:

Direct material used $ $280,000$

Direct labor $120,000$

Variable manufacturing overhead $160,000$

Fixed manufacturing overhead $100,000$

Variable selling and administrative cost $60,000$

Fixed selling and administrative cost $90,000$

Fort Smith$$s per$-$unit inventoriable cost under variable costing is:

Multiple Choice

$$9\mathrm{.}50.$

$$25\mathrm{.}00.$

$$28\mathrm{.}00.$

$$33\mathrm{.}00.$

$$40\mathrm{.}50.$