A cloth manufacturing firm is deciding whether or not to invest in new machinery. The machinery costs $45,000 and is expected to increase cash flows in the first year by $25,000 and in the second year by $30,000 . The firm's current fixed costs are $9,000 and current marginal costs are $15 . The firm currently charges $18 per unit. If the interest rate is 5% then the present value of the cash flows is

Refer to the diagrams. If $4 is Firm B's profit-maximizing price, its:

A.  ATC must be $4.
B.  MC must be $4.
C.  MR must be $4.
D.  MC must be zero.

Which of the following is a distinction between perfectly competitive and monopolistic competition?

A. Perfectly competitive firms must compete with rival sellers; monopolistically competitive firms do not confront rival sellers. B. Monopolistically competitive firms can raise their price without losing sales; perfectly competitive firms must lower their price in order to sell more of their product. C. Perfectly competitive firms confront a perfectly elastic demand curve; monopolistically competitive firms face a downward-sloping demand curve. D. Perfectly competitive firms may make either economic profits or losses in the short run, but monopolistically competitive firms always earn an economic profit.