Valu-Com Electronics manufactures five different models of telecommunications interface cards for PCs and laptops. As summarized in the following table, each of these devices requires differing amounts of printed circuit board, resistors, memory chips, and assembly. Hyper Link Fast Link Speed Link Micro Link Ether Link
Printed Circuit Board (square inches) 20 15 10 8 5
Resistors 28 24 18 12 16
Memory Chips 8 8 4 4 6
Assembly Labor (in hours) 0.75 0.6 0.5 0.65 1

The unit wholesale price and manufacturing cost for each model are as follows:
Per unit Revenues and Costs
Hyper Link Fast Link Speed Link Micro Link Ether Link
Wholesale Price $189 $149 $129 $169 $139
Manufacturing Cos $136 $101 $96 $137 $101

In its next production period, Valu-Com has 80,000 square inches of PC board, 100,000 resistors, 30,000 memory chips, and 5,000 hours of assembly time available. The company can sell all the product it can manufacture, but the marketing department wants to be sure the company produces at least 500 units of each product and at least twice as many FastLink cards as HyperLink cards while maximizing profit.

a. Formulate an LP model for this problem.
b. Create a spreadsheet model for this problem, and solve it using Solver.
c. What is the optimal solution?
d. Could Valu-Com make more money if it schedules assembly workers to work overtime?