Which alphabet letter is a question?

By including only four matchsticks in below picture, you have to make "Four Triangles And Two Squares"

There are two guys standing face to face in a room. On a wall, there is a clock. One of those is a prophet. He tells the other guy that he will be stabbed in the back in five minutes.

Shocked to hear that, the other guy stares at the clock. Just after the five minutes, he is stabbed on the back. Can you tell what happened?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

My location can be determined by the below rebus.
So where am i ?

If you say my name, I will no longer exist. What am I?

Find the next number in the series.
1 10 24 43 67 ?

You are in a land where thirty men and two women were dressed in classic black and white dresses.
They begin to fight as soon as any of them move.

Where are you?

Can anyone tell me a word in the English dictionary which has a silent 'z'?

What is both possible and impossible at the same time?