3. The network in Figure 5.10 shows the routes for shipping cars from three plants (nodes 1,
2, and 3) to three dealers (nodes 6 to 8) by way of two distribution centers (nodes 4 and
5). The shipping costs per car (in $100) are shown on the arcs.
(a) Solve the problem as a transshipment model.
(b) Find the new optimum solution assuming that distribution center 4 can sell 240 cars
directly to customers.