An appliance manufacturer produces two models of microwave ovens: H and W. Both models require fabrication and assembly work; each H uses four hours of fabrication and two hours of assembly, and each W uses two hours of fabrication and six hours of assembly. There are 600 fabrication hours available this week and 480 hours of assembly. Each H contributes $ 40 to profits, and each W contributes $ 30 to profits. What quantities of H and W will maximize profits?
a. Use the objective function approach.
b. Use the enumeration approach.