I am the one who remains awake when you sleep. But I need to rest when you awake. Who Am I?

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

There are two candles. Both will only burn exactly for an hour. How will you use these two candles to measure forty-five minutes?

A boy and his father are caught in a traffic accident, and the father dies. Immediately the boy is rushed to a hospital, suffering from injuries. But the attending surgeon at the hospital, upon seeing the boy, says 'I cannot operate. This boy is my son.' How is this situation explained?

A man is trapped in a room. The room has only two possible exits doors. Through the first door there is a room constructed from magnifying glass. The blazing hot sun instantly fries anything or anyone that enters. Through the second door there is a fire-breathing dragon. How does the man escape?

What work can one never finish?

I look at you, you look at me, I raise my right, you raise your left. What am I?

When is the top of a mountain similar to a savings account?

There was an aeroplane crash, every single person died, but two people survived. How is this possible?

Which number should replace the question mark?