If a person who weighs 100 lbs. is riding in an elevator and is joined by a person weighing 120 lbs., what happens to the average weight of persons on the elevator?

Amy can produce either 5,000 pounds of cheese or 20 cars per year. Mike can produce either 5,000 pounds of cheese or 10 cars per year. If both Amy and Mike produce the good in which they have comparative advantage, the total annual output of this economy will be ________.

A. 30 cars B. 10,000 pounds of cheese and 30 cars C. 5,000 pounds of cheese and 20 cars D. 10,000 pounds of cheese

A negative externality exists when

a. Jack buys a good from Bill, and this makes Bill worse off. b. Jack buys a good from Bill, and this makes Jack worse off. c. Jack buys a good from Bill, and this makes Todd better off. d. Jack buys a good from Bill, and this makes both of them worse off. e. Jack buys a good from Bill, and this makes Todd worse off.