A firm has a production function, Q = 3KL where Q is the level of output, K is the amount of capital and L is the amount of L. Supposed K is fixed at K̅ = 2 in the short-run, the rental rate of capital is r = 3 and the wage rate is w = 2.

a. Calculate and draw the following graphs: draw the total cost, variable cost, fixed cost in one graph and the average total cost, average variable cost, average fixed cost and marginal cost in the a separate diagram. What is the total cost to the firm if it want to produce Q = 180?

b. In the long run, capital is no longer fixed. Compute and sketch the long-run total cost, long-run average cost and long