Always in you, Sometimes on you;

If I surround you, I can kill you.

What am I?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

A new Engineering building containing 100 offices had just been completed. John was hired to paint the numbers 1 to 100 on the doors. How many times will John have to paint the number nine (9)?

There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

He does not have any heart but still, He manages to live.
If you kill him, you will eventually die but yet you kill him.
He cannot run, who is He?

You enter your friend's room. He is not in his room. Although you see that on the bed there are two dogs, five cats, two giraffes and three pigs. Also, a couple of chickens and ducks are flying in the room.

Calculate the number of legs standing on the floor.

If a wheel has 54 spokes, how many spaces are there between the spokes?

John was going on a jungle trip. He asked his wife to pack something to eat, something to drink and something to burn if he feels cold in the jungle. When John opens the backpack he found just one thing in the bag. What was it?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

The more you take me, the more you leave me behind.
Who Am I?