Below, you will find the mathematical proof that 10 equals 9.99999?. But is that possible or there is something wrong about it? Can you find the error?

x = 9.999999...
10x = 99.999999...
10x - x = 90
9x = 90
x = 10

No one wants to have it, but if one got it, he does not want to lose it. What is It?

What kind of band never plays music?

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?

The measurement of time, That can't be found on a clock, But can be looked upon on a map.

Who is He ?

You were playing ping pong with your friend. Suddenly the ball fell into a narrow metal pipe that was imbedded in the concrete surface of the floor one foot deep. Now you don't have any other ball and you desperately want to take it out and play. You and your friend have your shoelaces, your tennis paddle and a plastic water bottle. However, the bottle cannot fit into the pipe.

How will you take the ball out?

I can be made.
I can be cracked.
I can be told.
I can be played.

Who am I?

Move three sticks of the spiral below to form a square.

Can you make the number 24 by utilizing the numbers 1, 3, 4 and 6? You must use one number only one time and you can use mathematical operation symbols anytime anywhere.

There’s a girl who has a large family. She has an equal amount of brothers and sisters, but each brother only has half as many brothers and sisters. What’s the correct amount of brothers and sisters?