Christina has four daughters, and each of her daughters has a brother. How many children does Christina have?

We have shown you a regular water barrel as below. Without using any measuring device can you check if the barrel is more than half-filled or less than half-filled?

What does this rebus picture identify?

There are nine dots in the picture that has been attached with this question. Can you join all the dots by drawing four straight lines without picking up your pen?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

How can a man go eight days without sleep?

Imagine you are in a room with no windows or doors. How will you get out?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?

If I put in one canary per cage, I have one bird too many. If I put in two canaries per cage, I have one cage too many. How many cages and canaries do I have?

John was piloting a plane behind a car but was never able to overtake it. Why?