Explain whether LP techniques can be used in each of the following economic settings.
a. There are increasing returns to scale in production.
b. The objective function and all constraints are linear, but the number of decision variables exceeds the number of constraints.
c. The firm faces a downward-sloping linear demand curve. (To sell more output, it must lower its price.)
d. The firm can vary the amounts of two basic chemicals in producing a specialty chemical, but, for quality control reasons, the relative proportions of chemicals must be between 40/60 and 60/40.