The Suntrek Company is a global apparel retailer with stores around the world. It manufactures many of its clothing items in China and transports them by rail and truck to four ports on the coast—Hong Kong, Shenzhen, Yangshen, and Qingdao—where they are loaded into shipping containers for monthly shipment overseas to U.S. distributors. The company requires 25 total containers and the available containers at each port, the monthly leasing cost per container, the shipping time from each port to the United States, and the average percent damage historically incurred at each port are shown in the following table.

Ports Available Containers Container Cost ($)
Shipping Time (Days)
Percent Damage (%)
Hong Kong 9 270 25 2 Shenzhen 14 210 23 1.5 Yangshen 10 230 32 3 Qingdao 6 190 22 2 The company wants the average shipping time per container to be 24 days or less and the average percent damaged per container to be 2.5 percent or less. Formulate and solve an integer programming model to determine the number of containers Suntrek should lease at each port to minimize shipping costs.