A merchant sells shirts at a constant rate of 2000 per year. The cost of carrying a shirt in stock is $3 per year. The cost of ordering shirts is $50 per order plus $.20 per shirt. Approximately how many times per year should the merchant order shirts to minimize their total yearly costs? (Assume that orders can be placed so that shipments arrive precisely when stock is depleted.)

Note: This question is testing that I can set up and use derivatives to solve applied optimization problems.