Enpar manufactures engine parts for an automotive manufacturer. It operates two plants, A and B, which have the following production functions: QA = 30SA – 0.25SA2 and QB = 40SB – 0.5SB2, where QA and QB denote the outputs of engine parts from each plant and SA and SB denote the amounts of steel used in each plant. Suppose that total steel availability is 30 units. What is the optimal allocation of steel between the two plants?