Which alphabet letter is a question?

What has one letter and starts with an E?

It is always ahead of me yet I can never see it. What is it?

Christina is practising her dance steps along with her friends. In a particular sequence, all of them form a row. At that point, Niharika is standing in the 4th position from either end of the row.
Can you find out how many girls are practising together?

I speak without a mouth, and hear without ears. I have no-body, but I come alive with the wind. What am I?

You need to arrange three 7 and mathematical symbols to form number 1?

Assume the given figure to be a delicious doughnut. Yes, now you can concentrate more on the puzzle. So you have this delicious doughnut in your refrigerator when your friends come knocking at the door. There are eight of them. Now you have to make three cuts in this doughnut so that each one of you nine people can enjoy a piece of it. Neither you nor your friends would mind the size of their piece as long as they are getting it. How will you do it?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

If you read clockwise, you can form a word by inserting three missing letters in the picture given below. Can you do it?

A kind heart person buy packed food at 3$/packet from United states and sells them at 1$/packet at Africa. After some time he becomes a millionaire.

How come the guy become millionaire ?