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

which number am I?

If 2 workers can complete painting 2 walls in exactly 2 hours.

How many workers would be needed to paint 18 walls in 6 hours?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

When my father was 31 I was 8. Now he is twice as old as me. How old am I?

A deaf and mute man goes to the train station. Tickets for the train are 50 cents each. The man goes to the ticket booth and hands the man inside just a dollar. The man in the booth hands him two tickets.

How did the man in the booth know to give him two tickets without even looking at him?

Can you solve the below tricky visual equation?

John was visiting his friend Jacob. He found out that his friend's wife had just killed a burglar in self-defense.
John asks Jacob about what happened and he told that "His wife was watching television when suddenly the bell rang. She thought that it is her husband Jacob but she found the burglar who attacked her instantly and she got so frightened that she killed the burglar immediately with the knife.
John asked the police to arrest his friend's wife. Why?

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

It is deaf, Dumb and Blind!!!

Still, always tells the truth. What is it?

You have an empty wine bottle with a cork that has been secured at the top in a normal way. There is a metal ring inside the bottle that is suspended by a string.

How can you make the metal ring drop to the bottom if you are not allowed to touch anything - not the bottle, not the cork, not the thread and not the ring?