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

Can you decipher these quotes by Albert Einstein?
Blf xzm mvevi hloev z kilyovn lm gsv ovevo lm dsrxs rg dzh xivzgvw.

Look at the below sequence of letters and tell us what the next letter should be:

O T T F F S S ?

They are three errirs in this question. Can you find them?

Can you place six matchsticks in a manner that each of the matchsticks is in touch with the other five matchsticks?

In a school, there are four subjects. Seventy percent of students study English, seventy five percent of students study Science, eighty five percent of students study Mathematics and eighty percent of students study Spanish.

Can you calculate the percentage of students that study all four subjects?

Decode the movie name from the below picture?

You are trapped in a room with two doors. One leads to certain death and the other leads to freedom. You don't know which is which.
There are two robots guarding the doors. They will let you choose one door but upon doing so you must go through it.
You can, however, ask one robot one question. The problem is one robot always tells the truth, the other always lies and you don't know which is which.
What is the question you ask?

A man in a car saw a Golden Door, Silver Door and a Bronze Door. What door did he open first?

A king sentenced a man to the death sentence for some crime he had committed. Known for his kindness, the king told the culprit that he had a choice to die in a way he decides.

The culprit was clever and said something that saved him from death. What method do you think he must have chosen for his death?