Suppose a monopsonist hires its second worker and this person has a marginal labor cost of $75 per day. If the wage rate is now $62.50 per day, what was the wage rate of the first worker before the second was hired?

Suppose that at current consumption levels an individual's marginal utility of consuming an extra hot dog is 10 whereas the marginal utility of consuming an extra soft drink is 2 . Then the MRS (of soft drinks for hot dogs)—that is, the number of hot dogs the individual is willing to give up to get one more soft drink—is:

a. 5. b. 2. c. 1/2. d. 1/5.

Suppose that in a perfectly competitive market, firms are making an economic profit. In the long run, we know for sure that

a. some firms will leave the market b. the market price will rise c. the market supply curve will shift to the left d. economic profit will become zero e. production will be less than short-run production