I need help solving C and D.

Kalyan Singhal Corp. makes three products, and it has three machines available as resources as given in the following LP problem: Maximize contribution = 5X1 +4X2 + 3X3 1X1 +7X2 +4X3 = 90 2X1 + 1X2 + 7X2 = 96 8X1 + 4X2 + 1X2 = 90 X1, X2, X320 (Cy: hours on machine 1) (C2: hours on machine 2) (Cz: hours on machine 3) + a) Using a computer software for solving LP, the optimal solution achieved is: X1 = 7 (round your response to two decimal places). X2 = 6 (round your response to two decimal places). X3 = 10 (round your response to two decimal places). Contribution (objective value) = 89 (round your response to two decimal places). b) Machine 1 has 0 hours of unused time available at the optimal solution (round your response to two decimal places). Machine 2 has 0 hours of unused time available at the optimal solution (round your response to two decimal places). Machine 3 has 0 hours of unused time available at the optimal solution (round your response to two decimal places). dollars to the firm (round your response to two decimal places). Use sensitivity table to c) An additional hour of time available for third machine, is worth answer this questions. dollars (round your d) An additional 5 hours of time available for the second machine, at no cost to the firm, are going to increase the objective value by response to three decimal places). Use sensitivity table to answer this questions