How can you take 2 from 5 and leave 4?

Today, I celebrated my 32nd birthday but I was born in 1972.
How is this possible?

You have four chains. Each chain has three links in it. Although it is difficult to cut the links, you wish to make a single loop with all 12 links. What is the fewest number of cuts you must make to accomplish this task?

What has no start, end, or centre?

A man had five children. He had $100 with him to give to his children. He decided to start with the youngest child and then give $2 more than each younger child to his next elder child.

For example, if he gives $x to the youngest child, he will give $(x+2) to the next one, $[(x+2) + 2] to the next one and so on.

Can you find out how much did the youngest one receive?

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?

Two-person want to cross a river. Only one boat is present on the riverside that can carry only one person at a time.

However, they still manage to cross the river. How is it possible?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?

Three doctors said that Bill was their brother. Bill says he has no brothers. How many brothers does Bill actually have?

A pond had 60 fish, out of which, all but 20 died.
How many fishes are now present in that pond?