What has one letter and starts with an E?

You throw me out when you want to use me and you take me in when you don't want to use me.

Who Am I?

What have one eye but still cannot see?

While going to your grandmother's house, you counted Twenty houses on the right side. While returning back to your home, you counted Twenty houses on the left side.

How many houses are there between your home and your grandmother's home?

I am under you when I am whole.
I shift above you if you remove the first letter.
I come all around you if you remove the second as well.

Can you tell me who I am?

I know a nine-letter word having only one vowel.
Do you ?

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

He does not have any heart but still, He manages to live.
If you kill him, you will eventually die but yet you kill him.
He cannot run, who is He?

Before Mount Everest was discovered, what was the highest mountain in the world?

I get hot but I never sweat,
I cook food but I am not a chef,
I have a door but you can't enter me,
I have a light but I am not a lamp.
Who am I?