I have no doors but I have keys, I have no rooms but I have space, you can enter but you can’t leave! What am I?

How can a man go eight days without sleep?

I add 5 to 9 and get 2. The answer is correct, so what am I?

John was so frustrated to be the suspect of being a sleeper terrorist that he shoot himself right between the eyes with a revolver in his toilet. The revolver and the bullets were accurate. Minutes later John walks out of the toilet unharmed.
How can this be possible?

Solve the puzzle by telling what does below picture means.

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

Assume there are approximately 5,000,000,000 (5 billion) people on Earth. What would you estimate to be the result, if you multiply together the number of fingers on every person's left hand? (For the purposes of this exercise, thumbs count as fingers, for five fingers per hand.) If you cannot estimate the number then try to guess how long the number would be.

Two girls were born to the same mother, on the same day, at the same time, in the same month and year and yet they're not twins. How can this be ?

Take away my first letter, then take away my second letter. Then take away the rest of my letters, yet I remain the same. What am I?

Count the number of lines in the image below ?