Under absorption costing, STEPHCO had the following unit costs when 8,000 units were produced.

Direct labor $8.50 per unit

Direct material $9.00 per unit

Variable overhead $6.75 per unit

Fixed overhead ($60,000/8,000 units) $7.50 per unit

Total production cost $31.75 per unit

Compute the total production cost per unit under variable costing if 20,000 units had been produced.