If I remove one from eleven it becomes Ten and if I remove one from nine also becomes Ten. How?

Pronounced as one letter,
And written with three,
Two letters there are,
And two only in me.
I am double, I am single,
I am black blue and grey,
I am read from both ends,
And the same either way.

What word begins and ends with an E, but has only one letter?

You may enter, but you may not come in. I have space, but no room. I have keys, but open no lock. What am I?

This is a most unusual paragraph. How quickly can you find out what is so unusual about it? It looks so ordinary, you'd think nothing was wrong with it. Actually, nothing IS wrong with it. But it is not as ordinary as you might think. If you think about it for a bit, you will find out why it is truly so unusual. So what is it? What is so unordinary about this paragraph?

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

What breaks yet never falls, and what falls yet never breaks?

If,

A = 1

B = 2

C = 3

...

...

Z = 26.

Based on above rule, you need to find an eleven letter word whose letter sum is equal to 52.

What has many keys but can’t open a single lock?

Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?