Kent County Company produces a single product. The standard cost card for the product follows: Direct material Direct labor..... Variable overhead 3 pounds @ S4/pound - $12 per unit 2 hours @ S8/hour -S16 per unit 2 hours a $5/hour = $10 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