Posted by **Casey** on Saturday, March 3, 2012 at 9:54pm.

A sporting goods store sells 100 pool tables per year. It costs $20 to store one pool table for a year, based on the average inventory on hand. It costs $40 for each delivery of pool tables. How many times per year and in what lot size should the store order pool tables to minimize its inventory costs?

derivative way, help please?