(Answered) : Problem 1 A company in the southwest of France needs to transport 180 tons of chemical products stored in four depots D1 to D4 to

Problem 1 A company in the southwest of France needs to transport 180 tons of chemical products stored in four depots D1 to D4 to three recycling centers C1, C2, and C3. The depots D1 to D4 currently store respectively 50, 30, 35, and 65 tons of product and the recycling centers require 30, 65 and 85 tons, respectively. Two transportation modes are available: road and rail. Depot D1 only delivers to centers C1 and C2 by road at a cost of $12,000/ton and $11,000/ton, respectively; Depot D2 can deliver to C2, by road at a cost of $9,000/ton and