Best riddles


Taller than trees

What has roots as nobody sees, Is taller than trees, Up, up it goes And yet never grows?
A mountain.
86.00 %
40 votes



A man is found murdered on a Sunday morning. His wife calls the police, who question the wife and the staff, and are given the following alibis: the wife says she was sleeping, the butler was cleaning the closet, the gardener was picking vegetables, the maid was getting the mail, and the cook was preparing breakfast. Immediately, the police arrest the murdered. Who did it and how did the police know?
The maid. There is no mail on Sundays.
85.67 %
39 votes


Ant and Triangle Problem

Three ants are sitting at the three corners of an equilateral triangle. Each ant starts randomly picks a direction and starts to move along the edge of the triangle. What is the probability that none of the ants collide?
So let’s think this through. The ants can only avoid a collision if they all decide to move in the same direction (either clockwise or anti-clockwise). If the ants do not pick the same direction, there will definitely be a collision. Each ant has the option to either move clockwise or anti-clockwise. There is a one in two chance that an ant decides to pick a particular direction. Using simple probability calculations, we can determine the probability of no collision. P(No collision) = P(All ants go in a clockwise direction) + P( All ants go in an anti-clockwise direction) = 0.5 * 0.5 * 0.5 + 0.5 * 0.5 * 0.5 = 0.25
85.67 %
39 votes

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