Managers at the Transcontinent Shipping and Supply Company want to know the maximum tonnage of goods they can transport from city A to city F. The firm can contract for railroad cars on different rail routes linking these cities via several intermediate stations, shown in the following diagram; all railroad cars are of equal capacity:

7 6

10 A

5 2

4 9

3 3

D F

B E C

The firm can transport a maximum amount of goods from point to point, based on the maximum number of railroad cars shown on each route segment. Managers want to determine the maximum tonnage that can be shipped from city A to city F.

a. Formulate a linear programming model for this problem.

b. Solve the model by using the computer. LO.1