Final answer:
To minimize costs and meet a production target of Q = 20, the firm would choose the quantities of output QA and QB based on the given production functions. It involves solving an equation to find the optimal values of LA and LB and then substituting those values back into the production functions.
Step-by-step explanation:
The firm would choose the quantities of output QA and QB in order to minimize costs and meet a production target. To determine the optimal quantities, we need to set up a cost minimization problem and solve for the values of QA and QB. In this case, the production target is Q = 20, so we would set up the following equation: 0.5LA + 0.1LB = 20.For part (a), we can solve the equation to find the values of LA and LB. Once we have those values, we can substitute them back into the production functions QA = 0.5LA and QB = 0.1LB to find the quantities of output produced in each plant.