16. Super Sport Shoes, Inc., sells a special shoestring at a uniform rate of 2,400 pairs per year. The order cost is $10, and the holding cost is 20 percent of the unit cost. For less than 1,000 pairs, each pair of strings costs $0.22; from 1,000 to 1,499 pairs, each pair costs $0.20; and for 1,500 pairs or more, the cost is $0.18 per pair. What is the EOQ for this item?