So far, Top Guy already has a supplier of chino cloth. This supplier offers price discounts based on a certain quantity range. the price of chino cloth per yard is IDR 40,000. In one year, the average Top Guy needs 252,000 yards of chino cloth. In one order, Top Guy needs to pay Rp. 125,000. Top Guy already has a warehouse to store all fabric supplies. After going through the calculations, the storage cost for each roll of cloth is 1% of the price of the fabric. The following is a list of discounts given. Quantity (in yards) | Discount Prices

1-2000 | -

2001-4000 | 10%

4001-6000 | 20%

> = 6001 | 30%

based on data information 2,

a). Determine several prices from each order quantity range!

b). It is better if the order should be made for optimal costs?