When I got four, I have it none.
When I got two, I have it some.
When I got none, I have it all.

What is it?

Before Mount Everest was discovered, what was the highest mountain in the world?

How can you make number one disappear by adding something to it?

Akbar called Birbal and asked him to draw a line on the floor. He asked Birbal to make that line smaller without erasing it. Birbal smiled and did it before Akbar could blink his eyes.

How did he managed to do it?

What has many keys but can’t open a single lock?

Solve the mathematical equation in the picture below.

The answer I give is yes, but what I mean is no. What was the question?

A mad serial killer kidnaps people and forces them to play the game of 2 pills with them, In this game, there are pills in the table and one of them is normal pill while the other one is deadly poisonous.
The victim will choose one pill and the killer will pick the other pill and both simultaneously will swallow the pill with water.
victim dies every time.

One day the serial killer kidnaps the Joseph and forces him to play the same game with him.

Joseph solves the mystery of the two pills and remains alive.

Explain?

You have two rectangular wires.

Both of them have property that when you light the fire from one end , it will take 60 minutes to get completely burn.

However, they do not burn at consistent speed (i.e it might be possible 1st 20% burn in 50 minutes and 80% can burn in 10 minutes).

So how could you measure 45 minutes ?

There is a square of a particular number which when doubled, becomes 7 more than its quarter.

Can you find the number?