Question: You have two coconuts and you want to find out how high they can be dropped from a 100 story building before they break. But you only have $1.40 and the elevator costs a dime each time you ride it up (it's free for rides down).
How can you drop the coconuts to guarantee you will find the lowest floor they will break at, while starting and ending at floor 1?
Note: They break when dropped from the same height and they don't weaken from getting dropped.
Answer: You could drop it at floor 1 first (because you start at floor 1). Then you would go to the floors: 14, 27, 39, 50, 60, 69, 77, 84, 90, 95, 99, and 100. Whatever floor your first coconut breaks at, go to the floor above the last floor the coconut survived and drop the second coconut from this floor. Then go up by one floor until the second coconut breaks and that is the lowest floor it will break at.
Question: You are in a car with your friend and your car ran out of gas. You went to the gas station to go pick up some gas. You told your friend to close all the windows and don't turn the radio on. Your friend turned the radio on and the radio was the news reporting there is a murderer in town. Your friend looked up and saw the murderer. The murderer killed your friend. How is this possible?
Answer: Your car is a convertible. You didn't say to close the top roof.