The airline company Cloud 2 operates two aircrafts: the X1, which carries up to 40 passengers and 30 tons of cargo, and costs $500 per trip. the X2, which carries up to 60 passengers and 15 tons of cargo, and costs $600 per trip. The airline is contracted by their parent company to carry at least 600 passengers and at least 210 tons of cargo each day.

Lastly, the airline is contracted to provide at least 4 trips with the new X2 aircraft each day. The linear programming formulation is given as: X1 = number of trips to take using the X1 aircraft X2 = number of trips to take using the X2 aircraft + s.t. + +

, (a) List the extreme points of the feasible region. (b) How many daily trips should each aircraft make and what is the resulting cost? (c) Does the contractual obligation of at least 4 trips with the X2 aircraft affect Cloud 9's minimum cost? Why or why not?