uired demand is 4000 units, 3000 units and 2000 units for months 1, 2 and 3, respectively. Using regular-time labor, a maximum of 2600 units can be produced during each month at a cost of $35 per unit. Using over-time labor, unlimited units can be produced each month at a cost of $55 per unit. During each month, of all units produced (using regular and over time labor), 18% are defective and cannot be used to meet demand. At the end of each month, 10% of all units on-hand spoil and cannot be used to meet any future demands. After each month's demand is satisfied and spoilage is accounted for, a cost of $20 per unit in ending inventory is incurred. Assume that 800 usable units are available at the beginning of month 1. Determine how to minimize the total cost of meeting the demands for the next three months