Based on Westerberg, Bjorklund, and Hultman (1977).

Newcor’s steel mill has received an order for 25 tons of steel. The steel must be 5% carbon and 5% molybdenum by weight. The steel is manufactured by combining three types of metal: steel ingots, scrap steel, and alloys. Four individual steel ingots are available.

At most, one of each can be purchased. The weight (in tons), cost per ton, and the carbon and molybdenum content of each ingot are given in the file P06_68.xlsx.

Three types of alloys can be purchased. The cost per ton and chemical makeup of each alloy are also given in the file P06_68.xlsx. Steel scrap can be purchased at a cost of $100 per ton. Steel scrap contains 3% carbon and 9% molybdenum. Determine how Newcor can minimize the cost of filling its order.