Replace the question mark with the correct number below.

What is the riddle which can be asked all day with a different correct answer each time.

A pack of cards has 40 cards. You are blindfolded. Out of 40, 25 cards are facing down while 15 are facing up. You have been asked to divide this pack of cards into two decks - so that each deck contains an equal number of face-up cards. Remember, you are blindfolded.

How will you do it?

If one and a half boys, eat one and a half burgers in one and a half hours.

How many burgers can 9 boys eat in 3 hours?

John: "Hi Teacher, What is your favourite movie ?".
Chemistry Teacher: "Indium Cerium Platinum Iodine Oxygen Nitrogen".
Ten seconds later... John replied I got it.

Do you?

On a certain day, John celebrated his birthday. Two days later, his older twin brother Jacob celebrated his birthday.

Is this even possible? How can it be?

The peacock is a bird that does not lay eggs. How do they get baby peacocks?

Two batsman each on 94 runs. Seven runs needed to win in last 3 balls. Both make 100*. How?

Can you solve the maths in the below-given picture equation?

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?