What is both possible and impossible at the same time?

Can you find out the number that should replace the question mark with a valid reason?

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

I am a type of word that is spelt incorrectly or used differently, on purpose for humour. What am I?
Hint 1: You can find me in a joke.
Hint 2: I am a play on words.

There was a man he lives in a hotel each morning he presses the first floor button each evening if there is a person in the elevator he asks him to press the 10 floor button if there is no one in the elevator he takes the stairs why.

A Doctor always sneezes before the rain. Doctor sneezes, Will it rain?

What is the word or phrase?

In the picture that is attached with this question, you can find a square which comprises of four little squares inside it. Consider this square to be made with matchsticks. You have to remove two matchsticks such that only two squares remain instead of five.How will you do it ?

If all Goats are Sheep and all Sheep are Deers, are all Deers Goats ?

You are in a room with no metal objects except for two iron rods. Only one of them is a magnet.
How can you identify which one is a magnet?