What has lots of eyes, but can’t see?

They do not possess flesh or feathers or scales or bone
But still, they are blessed with fingers and thumbs of their own.

I am a three digit number.
My tens digit is five more than my ones digit.
My hundreds digit is eight less than my tens digit.
What number am I?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

Four men were in a boat on the lake. The boat turns over, and all four men sink to the bottom of the lake, yet not a single man got wet! Why?

If,

6 / 7 = 2
3 / 9 = 7
8 / 2 = 6

Then

4 / 5 = ?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

What does man love more than life, and hate more than death or mortal strife; that which satisfied men want; the poor have, and the rich require; the miser spends, the spendthrift saves, and all men carry to their graves?

Can you solve this amazing hard number series problem?
7, 8, 10, 12, 16, 18 ?

I come in different shapes and sizes.
Parts of me are curved, other parts are straight.
You can put me anywhere you like,
but there is only one right place for me.
What am I?