Answer:
The more that there is of this, the less you see. What is it?
A man was sitting on his couch and searching for the English Channel. How did he find it?
An archaeologist unearths a coin bearing the inscription "57BC". How does he instantly know that it's a forgery?
4 rubber ducks were floating in the bathtub, 2 floated away and 2 drowned. How many ducks are still alive?
When does 4 - 1 = 5 ?
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?