How can you make number one disappear by adding something to it?

The person who makes it has no need for it; the person who buys it has no use for it. The person who uses it can neither see nor feel it. What is it?

What Time Should the last watch show in the below figure?

Which wheel of car does not rotate when you turn your car right?

You can take four of the five letters out of this word, but the pronunciation never changes. What is the word?

For an extra income, John decided to work at a Hotel for one hour daily. The manager offers him that they will pay him $11 after every 11 days.
However, John offered a different proposition to the manager. The offers stand as:
He will be paid just a penny on his first day.
Two pence will be paid on the second day,
Four pence will be paid on the third day.
And so on till the 11th day.

Should the Hotel manager accept his offer?

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

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

What do you think with the below Picture ?

Here is what you have to do. You have to throw a ball as hard as you can but it must return back to you even if it does not bounce at anything. Also, you have nothing attached to the ball. There is no one on the other end to catch that ball and throw it back at you.

How will you do it?