You put $75 in the bank one year ago and forgot about it. The bank sends you a notice that you now have $81 in your account. What interest rate did you earn?

A perfectly competitive firm charges the market price of $18 to sell its product. The firm produces and sells the profit-maximizing quantity of 50 units at this price. Its average total cost is $17 and its average variable cost is $15. Which of the following statements is then true?

a. This firm should shut down now. b. At this current level of production, the firm's marginal cost is $17. c. At this current level of production, the firm's marginal cost is $15. d. The firm is earning an economic profit of $50

Adverse selection is

a. when people act differently because they are insured b. when more risk averse people want to be insured more c. when people at a greater risk want to be insured more d. when your guess at a test question is wrong