4 Steelco manufactures three types of steel at different plants. The time required to manufacture 1 ton of steel

(regardless of type) and the costs at each plant are shown in Table 8. Each week, 100 tons of each type of steel (1, 2, and 3) must be produced. Each plant is open 40 hours per week.

a Formulate a balanced transportation problem to minimize the cost of meeting Steelco’s weekly requirements.

b Suppose the time required to produce 1 ton of steel depends on the type of steel as well as on the plant at which it is produced (see Table 9, page 372). Could a transportation problem still be formulated?