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

There are four 3-link chains. All you have to do is join them into a big 12-link chain. For joining two closed links, one of the links must be cut and placed onto the other link for closing.

How many minimum links will you have to cut to make the big chain?

What is more useful when it is broken?

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

What have one eye but still cannot see?

You knock a Table over in the library, and suddenly 20 eyes are looking at you.

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.

I live in a bowl. I can swim. I have a tail. I also have fins and big eyes. What am I?

You can find some missing letters in the picture. By placing two particular letters in the spaces, you can form a nine lettered word beginning from one of the corners and going clockwise direction to the middle. Can you find out the letters and the word?

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