15. Combining raw materials M and M2 and labor, a company produces units of A. B, and C. The requ...
15. Combining raw materials M and M2 and labor, a company produces units of A. B, and C. The requirements and profit (excluding the cost of labor) for the production and sale of a unit of each are as follows: Mi (lb) M2 (lb) Labor (hr) Profit (S) 105 165 60 12 For the next month, the company has available 1 ton of Mi. 2.5 tons of M2, 500 hr of labor at $18/hr, and up to an additional 120 hr of overtime at $24/hr. (The company pays only for the labor used.) To determine an optimal production schedule, the company manager defines xi, x2, and x3 to be the number of A's, B's, and C's to be produced and x4 to be the number of hours of overtime to be used and formulates the following model: Maximizez 105x1+1 65X2+60X3 18(2x11 3x2lxs) 6x4 69x1+111x2 +42x3 -6x subject to 6xi 12x2 + 4x3 2000 16X1 + 25x2 + 7x3-5000 2xi 1 3x2+ X3 500+x4 14120 Adding four slack variables and applying the simplex algorithm, the reduced tableaux resolution initial and final tableaux only) are shown in Table 5.2 (a) What is the optimal production schedule, and what profit does it yield? (b) Write out the dual problem and determine an optimal solution point. (c) Several employees offer to work additional hours of overtime (at the same $24/hr rate). Should the manager accept their offer? (d) Suppose additional pounds of Mi could be purchased, at a cost of $7.75/lb over what the company now pays for the raw material. Should more be purchased?