4. (17pts) A process at ABC Pizza can produce 400 pizza pies per day (let this be the production rate); the firm operates 250 days per year. ABC Pizza has a cost of $180 per production run and a holding cost of $5 per pizza-year. Annual demand is 37,500 pies. No shortage is allowed. Assume 1 year has 250 days

a. (9 pts) What production run size (or batch size) should be used? (For the calculation, use DAY as the time unit.)

b. (8 pts) Consider the same pizza store. Here we can order pizza, instead of in-house production, for the business. The delivery lead time is zero. The ordering cost is $180 per order. What order size (or batch size) should be used? (For the calculation, use DAY as the time unit.)