Four cargo ships will be used for shipping goods from one port to four other ports (labeled 1, 2, 3, 4).
Any ship can be used for making any one of these four trips. However, because of differences in the
ships and cargoes, the total cost of loading, transporting, and unloading the goods for the different shipport
combinations varies considerably, as shown in the following table:
a. What is the total cost for all four shipments (optimal solution)