Why Aeroplane windows are round?

John replied, when asked how old he was. In 2 years he will be twice as old as he was five years ago.' How old is he ?

It's a test that will check your IQ.

Suppose you have one 11 minute hourglass and one 13 minute hourglass.

Can you measure exactly fifteen minutes using them ?

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

How much will a 38° angle measure when looked at under a microscope that magnifies ten times?

Two-person want to cross a river. Only one boat is present on the riverside that can carry only one person at a time.

However, they still manage to cross the river. How is it possible?

Can you find the thief by just looking at the picture below?

It begins where the time ends.
Its second is an expression of surprise.
Its third is a question.
Its fourth is urinate.
It ends with a drink.

Which country it is?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

How can you take 2 from 5 and leave 4?