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

A girl has as many brothers as sisters, but each brother has only half as many brothers as sisters. How many brothers and sisters are there in the family?

Once upon a time, three rivals got together in a dark wood on an open spot to compose a quarrel by using guns. It was a kind of duel but there were three people in it and therefore it was a truel. There were A, B and C. There were some rules to be followed in the game. The rules of the games were:
-They have to draw the lots in order to find who will fire first who will be second and who will be third.
- The next rule is that they will start firing on each other unless there is a last person alive.
- Each person will decide on his own about which person he will fire on.
-it is quite clear that A hits and kills in all the shots and it is 100%. Whereas 80% of the shots are hit by B and C hits 50% of the shots he tries to fire. the three persons have their strategies for firing. Nobody is killed by the stray bullet.

Question: who will have the highest chance of surviving in the truel and how much is the chance?

I travel all around the world but always stay in the corner. What am I?

A four-digit number (not beginning with 0) can be represented by ABCD. There is one number such that ABCD=A^B*C^D, where A^B means A raised to the B power. Can you find it?

You can see it everyday, But cannot touch it at will. What is it?

You walk into a room that contains a match, a kerosene lamp, a candle and a fireplace. What would you light first?

Find the last number in the series below:

voN luJ yaM raM ---

What do you call a fish without an eye?

A man stands on one side of a river, his dog on the other. The man calls his dog, who immediately crosses the river without getting wet and without using a bridge or a boat. How did the dog do it?