Answer:
What coin doubles in value when half is deducted?
How can you place a pencil on the floor so that no one can jump over it?
There are two sisters: one gives birth to the other and she, in turn, gives birth to the first. Who are the two sisters?
Twelve pears hanging high, twelve men passing by. Each took a pear and left eleven hanging there. How can this be?
Mr. Smith has two children. If the older child is a boy, what are the odds that the other child is also a boy?
What never gets any wetter no matter how hard it rains?