A standard deck of playing cards has 52 cards with 13 cards in each of the four suits; hearts, diamonds, spades, and clubs. If a single card is drawn from a standard deck, what is the probability that the card will be a spade?

If the bidders at a first-price auction have true values of $78, $72, $66, and $65, the item will sell for

a. $78 b. just under $78 c. $72 d. just over $72

Positive externalities arise when

A. a profitable firm is regulated. B. tax rates are reduced. C. an unprofitable firm is shut down. D. production of a good generates benefits that spill over to third parties.