An agribusiness company mixes and sells chicken feed to farmers. The costs of the chicken feed ingredients vary throughout the chicken feeding season but the selling price of chicken feed is independent of the ingredients. On August 1, management needs to know how many units of each of three grains (Q, R, and S) should be included in their chicken feed in order to produce the product most economically. The cost of each grain is, for a unit of Q, $30; for a unit of R, $37; and for a unit of S, $78. Applying linear programming to this problem, which of the following is the objective function?
HINT: Minimize Z where Z will be equal to $30 times the number of units of Q used PLUS $37 times the number of units of R used PLUS $78 times the number units of S used. Since we want to spend as little money as possible, we would like that mix of Q, R and S that will let Z be as small as possible.