It is based on the book "linear programming", ch 14, 15.

The following diagram represents the network for a transportation problem. The arrows into nodes A and B represent supply in the indicated amounts, 100 and 50 ; the arrows out of nodes E and F similarly represent demand in the amounts 30 and 120 . The remaining arrows indicate shipment possibilities, and the numbers on them are the unit shipping costs. There is a capacity of 80 . every arc. Write an LP model for finding a minimum-cost transport plan. Don't forget to write down what your variables and constraints mean. You do not need to solve the LP. The following diagram represents the network for a transportation problem. The arrows into nodes A and B represent supply in the indicated amounts, 100 and 50 ; the arrows out of nodes E and F similarly represent demand in the amounts 30 and 120 . The remaining arrows indicate shipment possibilities, and the numbers on them are the unit shipping costs. There is a capacity of 80 . every arc. Write an LP model for finding a minimum-cost transport plan. Don't forget to write down what your variables and constraints mean. You do not need to solve the LP