Sherlock Holmes was challenged to make a pre-drawn line smaller without erasing it. He did it in fractions of seconds. How?

There's one "sport" in which neither the spectators nor the participants know the score or the leader until the contest ends.

What is it?

Look at the picture and find out which square is not linked with any of the other squares.

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 given figure, you can see that four match sticks are used to form a square. Can you form five squares by using six matches?

My friends called me Iron59 because my parents are a chemist and a mathematician. What is my real name?

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

A man plots the murder of his wife. His plan is full proof. Nobody saw them leaving their house. He stabbed her with a knife while driving. She died on the spot. He threw her body in a valley. He threw the knife carefully wiping his finger prints on a random garbage bin. Then he went back to his home and no one was watching him this time as well.

After an hour, he was called by the local police department who informed him that his wife was murdered. They asked him to reach the scene of crime immediately. But as soon as he arrived at the crime scene, he was arrested by them.

How did the police know that he himself is the murderer?

What is the fastest way to double your money?

Find the hidden tiger in the given optical illusion ?