A quarter is an example of commodity money because the metal used to manufacture it has some value

Suppose that for a particular firm the only variable input into the production process is labor and that output equals zero when no workers are hired. In addition, suppose that when the firm hires 4 workers, the firm produces 50 units of output. If the fixed cost of production is $4, the variable cost per unit of labor is $20, and the marginal product of labor for the fifth unit of labor is 2,

what is the average total cost of production when the firm hires 5 workers? a. $2.00 b. $20.00 c. $20.80 d. $22.80

A profit-maximizing firm in the short run will expand output:

A. until total revenue equals total cost. B. as long as marginal revenue is greater than marginal cost. C. until marginal cost begins to rise. D. until marginal cost equals average variable cost.