Three types of gasoline are manufactured by a company – Regular, Super, and Extra. Regular should have at least 11 percent additive 1 and 17 percent additive 2. Super should have at least 13 percent additive 1 and 22 percent additive 2. Extra should have at least 17 percent additive 1 and 19 percent additive 2. These are made by using two crudes – A and B. Crude A cost $28 per barrel and is 14 percent additive 1 and 18 percent additive 2. Crude B costs $30 per barrel and is 20 percent additive 1 and 24 percent additive 2. The demand for Regular is projected to be 1,000 barrels, while each of the others has a demand of 2,000 barrels. Formulate this as a linear programming problem to minimize cost while meeting all constraints. Define all decision variables.