1. Consider Problem 1, Set 3.6a.

(a) Determine the optimality condition for ~ that will keep the optimum unchanged.

(b) Determine the optimality ranges for CA and C8, assuming that the other coefficient is kept constant at its present value.

(c) If the unit revenues CA and CB are changed simultaneously to $5 and $4, respectively, determine the new optimum solution.

(d) If the changes in

(c) are made one at a time, what can be said about the optimum solution?