There is an English word that can be used up to four times in a row without modifying the spelling and form a valid grammatical sentence.

Do you know what word is that?

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

I am weightless, but you can see me. Put me in a bucket, and I'll make it lighter. What am I?

John was working on a Chemical Mixture whose weight comprise 90% liquid and 10% solid. The total weight of the mixture is 20 pounds. After a while, John noticed that some of the liquid evaporated and now the liquid comprises just 50% of the weight.

What is the weight of the chemical mixture now?

There is a square piece of paper with a hole that is denoted by the circle on the top right side in the given picture. You have to cut the paper in a manner that it forms two and only two separate pieces of paper and then rearrange the pieces in a manner that the holes come in the centre of the paper.

Solve the counting riddle by identifying the number of triangles in the given picture.

They came out at night, without being called.
They lost at day, without being stolen.
Who are they?

The more you take me, the more you leave me behind.
Who Am I?

Can you convert the number zero(0) into a positive number using just one mathematical operator ?

A man hijacks an aeroplane transporting both passengers(8 of them) and valuable cargo. After taking the cargo, the man demands nine parachutes, puts one of them on, and jumps, leaving the other eight behind. Why did he want eight?