Rocky Mountain Tire Center sells

15,000

go-cart tires per year. The ordering cost for each order is

$40,

and the holding cost is

40%

of the purchase price of the tires per year. The purchase price is

$24

per tire if fewer than

200

tires are ordered,

$17

per tire if

200

or

morebut

fewer than

8,000tires

are ordered, and

$13

per tire if

8,000

or more tires are ordered.

a) How many tires should Rocky Mountain order each time it places an order?

b)

units (enter your response as a whole number).