Replace the question mark with the number below given a simple math problem.

You have two buckets - one holds exactly 5 gallons and the other 3 gallons. How can you measure 4 gallons of water into the 5 gallon bucket?

(Assume you have an unlimited supply of water and that there are no measurement markings of any kind on the buckets.)

If 5 cats catch 5 mice in 5 minutes, how long will it take one cat to catch a mouse?

There are 20 people in an empty, square room. Each person has full sight of the entire room and everyone in it without turning his head or body, or moving in any way (other than the eyes). Where can you place an apple so that all but one person can see it?

A bomb goes off.
Carnage.
One person, only a few feet away, survives! How can this be?

Decode the movie name from the below picture?

Many have heard it, but nobody has ever seen it, and it will not speak back until spoken to. What is it?

John was drowned by he was not wet. How?

Rearrange the letters in "new door" to make one word.

I got a bee but no honey.
got an eye but am still blind.
got a sea but no water.
got a tea but no coffee.
got a why but no answer.

What Am I?