Answer:
a.$20 per keyboard
Explanation:
The computation of the variable cost per computer keyboard is shown below:
= Direct material per unit + Direct labor per unit + Variable overhead per unit
= $10 per unit + $6 per unit + $4 per unit
= $20 per keyboard
Basically, we added the Direct material per unit, Direct labor per unit, and the Variable overhead per unit so that the variable cost per computer keyboard could come