Each desk-and-chair set requires 10 board feet of pine planks and 1.5 hours of direct labor. each set sells for $50. pine planks cost $.50 per board foot, and the division ends each month with enough wood to cover 10 percent of the next month’s production requirements. the division incurs a cost of $20 per hour for direct-labor wages and fringe benefits. the division ends each month with enough finished-goods inventory to cover 20 percent of the next month’s sales.