Please help with these questions

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

a. All inputs are variable.

b. All inputs are fixed.

c. Some inputs are variable and some inputs are fixed.

d. All inputs are increased in the same proportion.

2. In the long run,

a. All costs are variable costs.

b. All costs are fixed costs.

c. There are no variable costs.

d. b and c

e. All inputs are increased in the same proportion.

3. If the owners of a firm earn accounting profit, it follows that

a. They will earn economic profit, too.

b. Their explicit costs are greater than their implicit costs.

c. Their implicit costs are greater than their explicit costs.

d. They will not earn economic profit.

e. None of the above

4. Total costs are

a. Fixed costs plus average total costs.

b. Average fixed costs plus variable costs.

c. Fixed costs plus variable costs.

d. Fixed costs minus variable costs.

e. Fixed costs divided by total variable costs.

5. Constant 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. Smaller; rise

e. Equal; remain constant

6. The change in output that results from changing a variable input by one unit, holding all

other inputs fixed, is called the marginal __________ product of the variable input.

a. Physical

b. Value

c. Average

d. Explicit

7. Economies of scale are relevant to the __________, whereas the law of diminishing

marginal returns is relevant to the __________.

a. Long run; short run

b. Short run; long run

c. Industry; firm

d. Firm; industry

e. Firm in the short run; industry in the long run

8. __________ scale exist when inputs are increased by some percentage and output

increases by a smaller percentage, whereas __________ scale exist when inputs are increased

by some percentage and output increases by the same percentage.

a. Economies of; diseconomies of

b. Constant returns to; economies of

c. Diseconomies of; constant returns to

d. Diseconomies of; economies of

9. The main difference between the short run and the long run is that

a. Firms earn losses in the long run, but not in the short run.

b. The long run always refers to a time period of one year or longer.

c. In the long run, only one input can be fixed.

d. In the short run, one or more inputs are fixed.

10. The law of diminishing marginal returns

a. Is a short run concept.

b. Is a long run concept.

c. Is both a short run and a long run concept.

d. Does not hold in the real world.