What's the only room from which no one can enter or leave

If you remove one from eleven, it becomes ten. If you remove one from nine, it becomes ten.

How is this possible?

You can win me and lose me but never buy me
You can not eat me and never want to part with me
I can make you cry or bring you joy
I am not a machine and definitely not a toy
You keep me but i am not forever just yours
You might find me in a case or on a shelf next to a vase
I am hard and i am tall if you bump me i am sure to fall
I am made of different materials and am at many events
If your lucky and fight hard I might be yours
What am I ?

A rubber ball keeps on bouncing back to 2/3 of the height from which it is dropped. Can you calculate the fraction of its original height that the ball will bounce after it is dropped and it has bounced four times without any hindrance ?

You stand in front of two doors. A guard stands next to each door. You know the following things: one path leads to paradise, the other leads to death. You cannot distinguish between the two doors. You also know that one of the two guards always tells the truth and the other always lies. You have permission to ask one guard one question to discover which door leads to paradise. What one question would you ask to guarantee you enter the door to paradise?

A Child was born in Lahore, Pakistan. Still, the child is not a Pakistani citizen. why?

Most people think of me as money. But when they find me in the water, they won’t get any money out of me. What am I?

Readers with the sharpest vision can find the eagle in the mountains in 6 seconds. Are you one of them? Test your observation skills now!

I don't get anymore wetter, no matter how much rain falls on me.

How can you take 2 from 5 and leave 4?