When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

John is asked to stand behind Jacob and Jacob is asked to stand behind John. Both of them feel confused about it and don't know what to do?

But it is quite possible, do you know how?

The dirtier I get, the whiter I look. Who am I?

The answer I give is yes, but what I mean is no. What was the question?

In the Wild West, you are challenged into a death match by two bounty hunters nicknamed Golden Revolver (GR) and Killer Boots (KB). You accept the challenge. None of you want to waste any of the bullet and so a certain rules are laid down:

1) All of you will shoot in a given order till the last man standing.
2) Each of you shoots only once upon his turn.
3) If any one of you is injured, the other two will finish him off with an iron rod.
4) The worst shooter of all (which is you) shoots first and the best one shoots at the last.

Now, how will you plan things if you know that you hit every third shot of yours, KB hits every second shot and GR hits every shot ?

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

What number do you get when you multiply all of the numbers on a telephone's number pad?

What does the following represent?

N N N N N N N

A A A A A A A

C C C C C C C

What am I?

How can you write nineteen in a manner that if we take out one, it becomes twenty?