Answer:
An archaeologist unearths a coin bearing the inscription "57BC". How does he instantly know that it's a forgery?
10 fish are in a tank. 2 Drown, 4 Swim away, and 3 Die. How many are left?
What is as big as you are and yet does not weigh anything?
There are two sisters: one gives birth to the other and she, in turn, gives birth to the first. Who are the two sisters?
Dora died at a very old age on her 24th birthday. How can this be?
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?