Answer:
Twelve pears hanging high, twelve men passing by. Each took a pear and left eleven hanging there. How can this be?
An archaeologist digs up two perfectly preserved bodies. He immediately identifies them as Adam and Eve. How can he tell they are Adam and Eve?
Is an older one-hundred dollar bill worth more than a newer one?
What goes up the hill and down the hill, And spite of all, yet stand still?
10 fish are in a tank. 2 Drown, 4 Swim away, and 3 Die. How many are left?
Of these things - I have two. One for me - and one for you. And when you ask about the price, I simply smile and nod twice.