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?

In the city of Brain Teasers, 5% of people do not list their phone numbers. Now if we select random 100 people from the phone directory, then how many people selected will have unlisted phone numbers?

Find the next number in the sequence

5 12 24 36 ?

A mother is 21 years older than her child. In exactly 6 years from now, the mother will be exactly 5 times as old as the child.
Where's the father?

In the Chess Board picture below white army is arranged. You need to add a black army on the board such that no piece is under any threat.
Note: Army comprised of 1 king, 1 queen, 2 rooks, 2 bishops, 2 knights, and 8 pawns.

In two decks of cards, what is the least amount of cards you must take to be *guaranteed* at least one four-of-a-kind?

What has 13 hearts but no other organs?

What happened when the wheel was invented?

What do you answer even though it never asks you questions?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?