Note that problem 15(a), as presented in the text l, is infeasible as there is a constraint that x1 is less than or equal to 40 and a second constraint that x1 is greater than it equal to 80. Reward the problem to state x1 is greater than it equal to 40 and x1 is less than or equal to 80. In other words, the feasible space for x1 is between 40 and 80.

15. Solve the following LP problems graphically: (a) Maximize: Z=6x1 +5x2 Subject to: 3x1 +x,$ 160 X 1 $40 X2 130 X 1 2 80 X 1, X2 20 (b) Maximize: Z=7x+ 10x2 Subject to: X1