Question: You have been put in the basement of a building from which you can escape only by riding up to the ground floor on a coin operated elevator that requires $2. Someone passes you a $5 bill through the bars of the basement window. Fortunately, the elevator's money slot makes change. There is also in the elevator a video game that requires $0.50 per game.
a. What is the maximum amount of money that you can have left when you reach the ground floor?
b. What is the minimum amount of money that you can have left when you reach the ground floor?
c. How is this situation analogous to the photoelectric effect?