A man dies of old age on his 25 birthday. How is this possible?

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

Which letter of the alphabet has the most water?

What has many teeth, but cannot bite?

Replace the question mark with the correct number below.

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?

What do you get if you add 2 to 100 four times?

You have a basket containing ten apples. You have ten friends, who each desire an apple. You give each of your friends one apple.
Now all your friends have one apple each, yet there is an apple remaining in the basket.
How?

There are people and strange monkeys on this island, and you can not tell who is who (Edit: until you understand what they said - see below). They speak either only the truth or only lies.
Who are the following two guys?
A: B is a lying monkey. I am human.
B: A is telling the truth.

I have an eye but still cannot see.

Who am I?