20. During the war with Iraq in 1991, the Terraco Motor Company produced a lightweight, all terrain vehicle code-named "JQQTerra\" for the military. The company is now planning to sell the Terra to the pubiic. It has five plants that manufacture the vehicie and four regional distribution centers. The company is unsure of public demand for the Terra, so it is considering reducing its xed operating costs by closing one or more plants, even though it would incur an increase in transportation costs. The relevant costs lot the problem are provided in the following table. The transportation costs are per thousand vehicles shipped; for exampie, the cost of shipping 1,000 vehicies from plant 1 t0 warehouse C is $32,000. Transportation Costs Annual Annual Fixed ($10005) Production Operating to Warehouse C . ' Costs $05 12,000 $2,100,000 35 18,000 350,000 41 52 14,000 1,800,000 01 23 10,000 1,100,000 5 26 31 10,000 900,000 - - - Annual 0,000 14,00 10,000 Deman 0 d Formulate and solve an integer programming model for this probiern to assist the company in determining which plants shouid remain open and which should be closed and the number of vehicles that should be shipped from each pian to each warehouse to minimize total cost