Please help me with these Questions

21. The theory of oligopoly assumes

a. A few sellers and many buyers.

b. A few buyers and many sellers.

c. Significant barriers to entry.

d. a and c

e. None of the above.

1. Which of the following statements is true?

a. Costs are always explicit, never implicit.

b. Costs are always implicit, never explicit.

c. Allen runs a stationery shop; he paid Joseph $5,000 for the carpet he installed in the

shop. The $5,000 for carpet is an implicit cost.

d. An implicit cost is a cost that represents the value of resources used in production for

which actual payment will be made in the future.

e. None of the above

1. The law of diminishing marginal returns holds for a situation in which

a. All inputs are variable.

b. All inputs are fixed.

c. All inputs are decreased in the same proportion.

d. All inputs are increased in the same proportion.

e. None of the above.

1. Decreasing returns to scale are said to exist when inputs are increased by some percentage

and output increases by a(n) __________ percentage, causing unit costs to __________.

a. Greater; fall

b. Smaller; fall

c. Greater; rise

d. None of the above

1. In a pure monopoly situation product price:

a. And production are the same as they would be in perfect competition.

b. And production are higher than they would be in perfect competition.

c. Is lower and production higher than they would be in perfect competition.

d. Is higher and production lower than they would be in perfect competition.

e. And production are lower than they would be in perfect competition.

26. Which of the following are government policies to control the abuses of imperfect

competition?

a. Taxes

b. Price controls

c. Regulation

d. Antitrust policy

e. All of the above

27. Which of the following could affect a demand schedule for petroleum products?

a. A change in the technology of oil production.

b. The discovery of new oil fields in Texas.

c. A strike by oil refinery workers.

d. An increase in national income.

e. None of the above.

28. Dalia is given a flu shot by her doctor. This reduces the probability that she will get the

flu and it also reduces the probability that others will get the flu, too. The latter is an example

of a

a. Negative externality.

b. Substitute good.

c. Complementary good.

d. Positive externality.

29. If we know each producer's supply curve, we can derive the market supply curve by:

a. Summing the individual supply curves.

b. Averaging the individual supply curves.

c. Horizontally summing the individual supply curves

d. Obtaining producers incomes and summing them.

e. Vertically summing the individual supply curves.

30. Which of the following statements is true?

a. A monopolist can charge whatever price it wants without losing any customers, by virtue

of its monopoly position.

b. A monopolist can always increase its profits by increasing its price.

c. In the monopoly market structure, there are low barriers to entry.

d. A monopolist is assured of positive economic profits.

e. None of the above