The first box has two white balls. The second box has two black balls. The third box has a white and a black ball.

Boxes are labeled but all labels are wrong!

You are allowed to open one box, pick one ball at random, see its colour and put it back into the box, without seeing the colour of the other ball.

How many such operations are necessary to correctly label the boxes?

A woman is sitting in her hotel room and hears a knock at the door. She opens the door to see a man whom she’s never met before. He says, “I’m sorry, I have made a mistake, I thought this was my room.” He then goes down the corridor and into the elevator. The woman goes back into her room and calls security. What made the woman so suspicious of the man?

Do You See It?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

What does the below image rebus riddle means ?

A girl has as many brothers as sisters, but each brother has only half as many brothers as sisters. How many brothers and sisters are there in the family?

Irene killed hundreds of people mercilessly and yet the police were not able to put her behind the bars. Why?

I am a prime number.
The double of myself is equal to the square of me.

which number am I?

The day after tomorrow will be three days before Tuesday. Can you find out what is today?

Can you find the key in the picture below?