A certain street contains 100 buildings. They are numbered from 1 to 100. How many 9's are used in these numbers?

What you cannot hold but it is yours?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

You knock a Table over in the library, and suddenly 20 eyes are looking at you.

I am beautiful, up in the sky. I am magical, yet I cannot fly. To people I bring luck, and to some people, riches. The boy at my end does whatever he wishes. What am I?

I am the beginning of the end, and the end of time and space. I am essential to creation, and I surround every place. What am I?

What is more useful when it is broken?

Two in a corner, one in a room, zero in a house, but one in a shelter. What is it?

If an electric train is travelling south, then which way is the smoke going?

I have four wings but can't fly.
I express no emotions.
I am found on the exact spot every time you look.
I keep toiling away with a little sound.

Do you know what am I?