When I get multiplied by any number, the sum of the figures in the product is always me. What am I?

I am taken from a mine and shut up in a wooden case, from which I am never released, and yet I am used by almost every person. What am I?

I sleep during the day and fly at night, but I have no feathers to aid my flight. What am I?

Give it food and it will live; give it water and it will die.

These types of puzzles are known as charades. What you have to do is 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 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 white when I am dirty, and black when I am clean. What am I?

Samuel was out for a walk when it started to rain. He did not have an umbrella and he wasn't wearing a hat. His clothes were soaked, yet not a single hair on his head got wet. How could this happen?

Can you name any English verb that becomes its past tense by simply rearranging the alphabets ?

It comprises roots which nobody sees,
Much taller than those trees,
Up and up it goes,
Still it never grows?

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?