For the P & T Co. problem described in Sec. 9.1, suppose that there is a 10 percent discount in the shipping cost for all truckloads beyond the first 40 for each combination of cannery and warehouse. Draw figures like Figs. 13.3 and 13.4, showing the marginal cost and total cost for shipments of truckloads of peas from cannery 1 to warehouse 1. Then describe the overall nonlinear programming model for this problem.