Three friends named Mr. Black, Mr. Yellow and Mr. Green enter a pub on a weekend night. They are wearing either a Black, Yellow or Green shirt.

Mr. Yellow says to them, 'Did you notice that we all are wearing different color shirts than our names?'

To this, the man who was wearing the Green shirt said. 'Wow, thats right.'

Can you identify who is wearing which colour shirt ?

John is asked to stand behind Jacob and Jacob is asked to stand behind John. Both of them feel confused about it and don't know what to do?

But it is quite possible, do you know how?

I know a 5-digit number having a property that With a 1 after it, it is three times as large as it would be with a one before it.

Guess the number?

Begin with a word, five letters to my name,
Remove the first and last but I am the same
Take out my middle and still, I remain.
What word am I?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

Using Only Five 5's and any mathematical operator make sum as 37

What word begins and ends with an E, but has only one letter?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?