Rocky Mountain Tire Center sells 7,0000 ?go-cart tires per year. The ordering cost for each order is ?$35 and the holding cost is 40?% of the purchase price of the tires per year. The purchase price is ?$20 per tire if fewer than 20 tires are? ordered,?$18 per tire if 200 or? more, but fewer than 5,000, tires are? ordered, and ?$14 per tire if 5,000 or more tires are ordered.
?a) How many tires should Rocky Mountain order each time it places an? order? Optimal order quantity is?
?b) What is the total cost of this? policy?