12. Suppose a firm has the following production function: Q = 2KL. The marginal product of capital for this production function is 2L, and the marginal product of labor is 2K. If capital rents for $100 per unit per day, labor can be hired for $200 per unit per day, and the firm is minimizing costs,

a. What is the total cost of producing q units of output?

b. What is the average cost of producing q units of output?

c. What is the marginal cost of producing q units of output?