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

A mathematics teacher took exams for his students. Out of the total students, 25% passed both the tests included in the exam. However, only 42% were able to clear the first test.

Can you find out the percentage of those students who passed the first test and also passed the second test?

You visit a home for specially-abled children on the occasion of Christmas where you meet with 50 children. You have a box of chocolates containing 50 chocolates exactly.

What if you were asked to one chocolate to each child in a manner that one chocolate still remains in the box? Is it possible?

You are in a room with no metal objects except for two iron rods. Only one of them is a magnet.
How can you identify which one is a magnet?

Can you fill the blank with the correct number?

6 30 870 756030 _____

These types of puzzles are known as charades. What you have to do is to find two words that are referred to in the first stanza and the second stanza and put them together to form the third word in the third stanza.

Just for example, if my first refers to 'off' and my second refers to 'ice', then my whole will be the 'office'.

My first is present - future's past -
A time in which your lot is cast.

My second is my first of space
Defining people's present place.

My whole describes a lack of site -
A place without length, breadth, or height.

I am a normal creature, but I have five hands. I can even have more but even then I will be considered normal.

Who am I?

What am I?

What has six faces, but does not wear makeup, has twenty-one eyes, but cannot see? What is it?

I make a loud sound when I’m changing. When I do change, I get bigger but weigh less. What am I?