\begin{tabular}{|c|c|c|c|c|} \hline Grill Model & Selling Price/Unit & VariableCost/Unit & MinimumMonthlySalesRequirements & MaximumMonthlySalesPotential \\ \hline A & $250 & $210 & 0 & 4,000 \\ \hline B & $300 & $240 & 0 & 3,000 \\ \hline C & $400 & $300 & 500 & 2,000 \\ \hline D & $650 & $520 & 500 & 1,000 \\ \hline \end{tabular} Suppose that a manufacturer makes four models of a product and must decide how many units of each product to produce in a given time period to maximize profit. A manufacturer of gas cooking grills produces products A, B, C, and D. Each grill must flow through five departments in the manufacturing plant: stamping, painting, assembly, inspection, and packaging. Relevant data are shown in Figure 6-2 \begin{tabular}{|l|c|c|c|c|c|} \hline Department & A & B & C & D & HoursAvailable \\ \hline Stamping & 40 & 30 & 10 & 10 & 320 \\ \hline Painting & -- & 20 & 10 & 10 & 320 \\ \hline Assembly & 25 & 15 & 15 & 12 & 320 \\ \hline Inspection & 20 & 20 & 25 & 15 & 320 \\ \hline Packaging & 50 & 40 & 40 & 30 & 320 \\ \hline \end{tabular} Here the production rates are given for making each grill model in each department. For example, in the stamping department, grill A is made at a rate of 40 per hour (note: grill A is not painted). Given these data, how many units of each grill model should the manufacturing plant make in order to maximize monthly profit