Park Seo Jun is a business enterprise located in the city of Seoul. The market price on a per unit basis is P3,000. Since Seoul is a very progressive rural place, the business sells on average of 35,000 tires annually. Based on a company study covering the last five years of its operations, it was found out that annual carrying cost per tire is P5.00 and the ordering cost isP100 on a per order basis. The store is open 7 days a week (which includes Sundays and holidays of obligation). The delivery time per order (tires are ordered from Manila) is 5 days. Since it normally takes time before an order is placed, filled up and delivered, the manager has decided to keep a safety stock of 3,000 tires which is equivalent to a month's sales. The average inventory is