The average age of 10 members of a committee is the same as it was 4 years ago, because an old member has been replaced by a young member. Find how much younger is the new member ?

Decode the below four famous ciphers:

8P of the SS
1M of the E
1S of the SS
60M in 1H

Count the number of triangles in the picture below:

Can you identify if it's a murder or a suicide ?

It is a nine-letter word.
The exact opposite of the phrase "friendly and outgoing"
It contains the word "over".
It starts will a vowel.

What is it?

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

A woman lives in a skyscraper thirty-six floors high and is served by several elevators which stop at each floor going up and down. Each morning she leaves her apartment and goes to one of the elevators. Whichever one she takes is three times more likely to be going up than down. Why?

Can you think of any three-dimensional shape that comprises of exactly two surfaces?

How can you make the following equation true by drawing only one straight line: 5+5+5=550 ?

You have two strings whose only known property is that when you light one end of either string it takes exactly one hour to burn. The rate at which the strings will burn is completely random and each string is different. How do you measure 45 minutes?