Answer:
What goes up and never comes down?
How do you drop an egg and never break it?
On which day of the year do fewest people die?
There are two sisters: one gives birth to the other and she, in turn, gives birth to the first. Who are the two sisters?
Three doctors said that Bill was their brother. Bill said he had no brothers. Who was lying?
What goes around and around the wood, but never goes into the wood?