Move four matchsticks to the below square to form three squares?

What is black when you buy it, red when you use it, and gray when you throw it away?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

How can a man go eight days without sleep?

In this image, you can see three almost identical Doraemon images. Can you spot the odd one out from them?

What is at the end of a rainbow?

Readers with high attention to detail can identify the vampire in the picture. Can you?

Can you solve the below rebus?

If your uncle’s sister is not your aunt, what relation is she to you?

There is a bag which have 21 blue balls and 23 red balls. You also have 22 red balls outside the bag. Randomly remove two balls from the bag. * If they are of different colors, put the blue one back in the bag. * If they are the same colour, take them out and put a red ball back in the bag. Repeat this until only one ball remains in the bag. What is the color of the sole ball left in the bag ?