a) HairGlow uses a chemical in the production of one of its hair products at a rate of 1,000 litres per year. The cost of placing an order and of receiving the chemical once it arrives in the warehouse is Ksh 30 and Ksh 70 respectively. The chemical is purchased at Ksh 20 per litre. Holding costs per year for a litre of the chemical is considered to be 15 percent of its cost. Find the optimal order size, the average inventory cost per year, and the length of an inventory cycle. b) OfficePro sells calculators at a rate of 3 per day. When the company places an order from its supplier, the lead time varies. The distribution of the lead time is: L (in days) 8 9 10 11 12 13 P(L) 0.3 0.3 0.2 0.08 0.07 0.05 The company has already found the optimal order size is 80 calculators. What should be the reorder level if the company will take no more than a 10 percent chance of being out of calculators when an order is placed