Which alphabet letter is a question?

What has one letter and starts with an E?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

Solve The below Equation:

ALFA + BETA + GAMA = DELTA

What you cannot hold but it is yours?

Can you make four (4) nines (9) equal 100?

I have nine bottles of wine and one of the nine bottles is poisoned.
I need to find the poisoned bottle with two facts
(1) Poison is deadly, only a sip will cost death
(2) I have two mice to do so.

How should I do it?

In the picture given below, can you find out which digit will take place of the question mark?

If two fifty-foot ropes are suspended from a forty-foot ceiling that is twenty feet apart, how much rope will you be able to steal if you have a knife?

A prisoner is told: "If you tell a lie, we will hang you and if you tell the truth, we will shoot you." What did the prisoner say to save himself?