You find yourself in a strange place guarded by two guards.One of the guard always say truth while other always lies.You don't know the identity of the two.You can ask only one question to go out from there. What should you ask?

An infinite number of mathematicians are standing behind a bar. The first asks the barman for half a pint of beer, the second for a quarter pint, the third an eighth, and so on. How many pints of beer will the barman need to fulfill all mathematicians' wishes?

There are three light switches outside a room. One of the switches is connected to a light bulb inside the room.
Each of the three switches can be either 'ON' or 'OFF'.

You are allowed to set each switch the way you want it and then enter the room(note: you can enter the room only once)

Your task is to then determine which switch controls the bulb?

When you say goodbye, I am what you need to tie.
I come as a couple and go wherever you run.
Who am I?

Manish has to secure 40% marks to pass his B.tech final exams.
He got just 40 marks and failed by 40-marks.

What is the maximum marks?

Move four matchsticks to the below square to form three squares?

In the given picture, in how many ways can you read the word "Tiger"?

What number should come in place of the question mark below?

What is more useful when it is broken?

What is the fewest number of coins that would be required in order to make sure each and every coin touches exactly three other coins?