# Simple riddles

## I travel all over the world

I travel all over the world. But I could not move, just stay in a same single spot. What Am I?
A stamp.
77.36 %

## Ants on a Board

There are 100 ants on a board that is 1 meter long, each facing either left or right and walking at a pace of 1 meter per minute. The board is so narrow that the ants cannot pass each other; when two ants walk into each other, they each instantly turn around and continue walking in the opposite direction. When an ant reaches the end of the board, it falls off the edge. From the moment the ants start walking, what is the longest amount of time that could pass before all the ants have fallen off the plank? You can assume that each ant has infinitely small length.
The longest amount of time that could pass would be 1 minute. If you were looking at the board from the side and could only see the silhouettes of the board and the ants, then when two ants walked into each other and turned around, it would look to you as if the ants had walked right by each other. In fact, the effect of two ants walking into each other and then turning around is essentially the same as two ants walking past one another: we just have two ants at that point walking in opposite directions. So we can treat the board as if the ants are walking past each other. In this case, the longest any ant can be on the board is 1 minute (since the board is 1 meter long and the ants walk at 1 meter per minute). Thus, after 1 minute, all the ants will be off the board.
77.36 %

## Whoever...

Whoever makes it, tells it not. Whoever takes it, knows it not. Whoever knows it, wants it not.
Counterfeit money.
77.32 %

## An ancient invention

What is the ancient invention that allows people to see through walls?
A window.
77.29 %

## Until I am measured I am not known

Until I am measured I am not known. Yet how you miss me when I have flown.
Time.
77.26 %

## Everyone has to face me

Sometimes I am loved, usually by the young. Other times I am dreaded, mostly by the old ones. I am hard to remember, also hard to forget. And yet if you do, You'll make someone upset. I occur every day everyone has to face me. Even if you don't want it to happen; embrace me. What am I?
Birthday.
77.25 %

## German/Swiss border

A woman who lived in Germany during World War II wanted to cross the German/Swiss border in order to escape Nazi pursuers. The bridge which she is to cross is a half mile across, over a large canyon. Every three minutes a guard comes out of his bunker and checks if anyone is on the bridge. If a person is caught trying to escape German side to the Swiss side they are shot. If caught crossing the other direction without papers they are sent back. She knows that it takes at least five minutes to cross the bridge, in which time the guard will see her crossing and shoot her. How does she get across?
She waits until the guard goes inside his hunt, and begins to walk across the bridge. She gets a little more than half way, turns around, and begins to walk toward the german side once more. The guard comes out, sees that she has no papers, and sends her "back" to the swiss side.
77.25 %

## Number which is spelled in an alphabetical order

I know a number which is spelled in an alphabetical order. Do you?
Forty.
77.23 %

## 20 blackbirds on a fence

If 20 blackbirds are on a fence and you shoot one, how many remain?
None, they would all fly away from the sound of the shot.
77.23 %