Please solve it in the normal way without using programs.

3. Saudi Computers purchases integrated chips at SAR 350 per chip. The holding cost is SAR 35 per unit per year, the ordering cost is SAR 120 per order, and sales are steady, at 400 per month. The company's supplier, Green Chip Manufacturing, Inc., decides to offer price concessions in order to attract larger orders. The price structure is shown below. QUANTITY PURCHASED PRICE/UNIT 1-99 units SAR 350 100-199 units SAR 325 200 or more units SAR 300 a. What is the optimal order quantity and the minimum annual cost for Saudi Computers to order, purchase, and hold these integrated chips? b. Saudi Computers wishes to use a 10% holding cost rather than the fixed SAR 35 holding cost in (a). What is the optimal order quantity, and what is the optimal annual cost