Kent County Company produces a single product. The standard cost card for the product follows: Direct material 3 pounds @ 4 pound = $12 per unit Direct labor 2 hours @ $8/hour - $16 per unit Variable overhend 2 hours @ $5/hour - S10 per unit During a recent period the company produced 500 units of product. Various costs associated with the production of these units are given below: Units produced Direct material used Direct material purchased (3,000 pounds) Direct labor cost (950 hours) Variable overhead cost incurred 500 1,600 pounds $12,300 $7,790 $4,655 The variable overhead efficiency variance is: $500 F $500 U $245 F $250 F