How to identify to solve the transportation method-linear programming ?

116. Houma Containers, Inc., makes industrial fiberglass tanks that are used on offshore oil platform Demand for the next four months and capacities of the plant are shown in the table below. Unit on regular tune is $400. Overtime cost is 150% of regular time cost. Subcontracting is available substantial quantity but at a very high cost, $1 100 per unit. Holding costs are $200 per tank per month: back orders cost the firm $1000 per unit per month. Houma's management believes that transportation algorithm can be used to optimize this scheduling problem. The firm has no beginning inventory and anticipates no ending inventory March April May June Demand 300 500 300 350 Regular capacity 200 200 250 250 Overtime capacity 50 50 50 50 Subcontract cap 150 100 100 150 a How many units will be produced on regular time in June? b. How many units will be produced by subcontracting over the four-month period? c. What will be the inventory at the end of April? d. What will be total production from all sources in April? e. What will be the total cost of the optimum solution? f. Does the firm utilize the expensive options of subcontracting and back ordering? When: why