Answer:
What is the building that you leave without ever having entered.
On which day of the year do fewest people die?
When can you add two to eleven and get one as the correct answer?
What coin doubles in value when half is deducted?
There is a dog on one side of a lake and a woman on the other. The woman calls the dog over and when he gets there he is not wet at all. How is this possible?
I stand in one place yet fill the whole room. I can be filled with molten rock and come in every hue. What am I?