The square root of number 121 is "11". What is the square root of the number "12345678987654321."?

A maths symbol is hidden in the below Bar Graph. Can you decipher it?

John is found dead in a bare field. Nobody killed John,
John did not commit suicide.

Inspector Jacob found a bag just a few meters away from John which could save his life. What was in the bag?

Is the statement valid that it does not matter how much older a sibling is, eventually the younger one will be half as old as the older one?

There are 2 sand hourglasses.

The small one can measure 5 hours and the large one can measure 7 hours.

How can we measure 16 hours with 2 sand hourglasses running together ?

How is a fly different from a mosquito?

You see a boat filled with people, yet there isn’t a single person on board. How is that possible?

The day after tomorrow will be three days before Tuesday. Can you find out what is today?

Here is what you have to do. You have to throw a ball as hard as you can but it must return back to you even if it does not bounce at anything. Also, you have nothing attached to the ball. There is no one on the other end to catch that ball and throw it back at you.

How will you do it?

If,
9 * 8 * 7 = 65
8 * 7 * 6 = 50
7 * 6 * 5 = 37

Find
6 * 5 * 4 = ?