Pollution Control. Three types of coal, C1, C2, and C3, are pulverized and mixed together to produce 50 tons per hour needed to power a plant for generating electricity. The burning of coal emits sulfur oxide (in parts per million) which must meet the EPA specifications of no more than 2000 parts per million. The following table summarizes the data of the situation:

C1 C2 C3 Sulfur (parts per million) 2500 1500 1600 Pulverizer capacity (ton/hr) 30 30 30 Cost per ton $30 $35 $33 Determine the optimal mix of the coals.