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

10 people came into a hotel with 9 rooms and each guest wanted his own room. The bellboy solved this problem.
He asked the tenth guest to wait for a little with the first guest in room number 1. So in the first room, there were two people. The bellboy took the third guest to room number 2, the fourth to number 3, ..., and the ninth guest to room number 8. Then he returned to room number 1 and took the tenth guest to room number 9, still vacant.
How can everybody have his own room?

Which city is three-fifths chick two third cat and 50% goat?

What is the word or phrase?

I am white when I am dirty, and black when I am clean. What am I?

Can you solve the tricky chess rebus puzzle below by ciphering the hidden meaning?

You are given four results as below:
1111 = F
2222 = E
3333 = T
Then, can you find out how to code 4444?

What jumps when it walks and sits when it stands?

10+10 and 11+11 can give you the same answer.

Explain how?

You bought me for dinner but never eat me. What am I?