In the city of Brain Teasers, 5% of people do not list their phone numbers. Now if we select random 100 people from the phone directory, then how many people selected will have unlisted phone numbers?

A chess tournament is taking place on knock-out terms (the one who loses the match is out of the game).
(a) If 10 matches are played in total, how many players participated?
(b) If 20 players took part in the tournament, how many matches were played?

When is the top of a mountain similar to a savings account?

French Police inspects a room where there are no windows, no doors, no tables and is almost empty expect there is just a puddle of water. They found a dead man who obviously hung herself from the ceiling, but they are not able to figure out how this had happened.

John and Jacob entered the crime scene and easily able to solve the case.

How did the man die?

I got a bee but no honey.
got an eye but am still blind.
got a sea but no water.
got a tea but no coffee.
got a why but no answer.

What Am I?

This is a classy optical illusion puzzle. What more you can find except bricks in the image below?

Who is that with a neck and no head, two arms and no hands? What is it?

If it took eight men ten hours to build a wall, how long would it take four men to build it?

How can a man go eight days without sleep?

I am a white box having no key or lid.
Yet there is a golden treasure inside it.

What Am I?