An eyeglass retailer buys lenses from a supplier at $100 each. The retailer orders 250 lens pairs every year and the ordering cost is $36 for each pair. Carrying costs per year (based on average inventory) are estimated to be 20 percent for each pair. The supplier offers a 10 percent on order quantities of 50 or more lens pairs. Determine the best order quantity and total cost.

An electronic store sells 3,000 HD TV sets every quarter of the year. Each TV set costs the store $ 270.00. The carrying cost is set at 2% of the purchase price per unit per year. Each time an order is placed it costs the store $ 120.00 The supplier charges $10 for delivery of each order. Calculate:

a. Optimal order quantity

b. Number of orders per year

c. The supplier is willing to give a discount of 3% on the price of each set if the manager of the store orders 3,000 sets at a time. Should the manager accept the offer?