There are a number of books on a shelf. If one book is the 4th from the left and 6th from the right, how many books are on the shelf?

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

If eleven plus two equals one, what does nine plus five equal?

I have a clock(12-hour format) and both the needles of the clock overlap at 12:00.
After how much time, they will overlap again?

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

I came first on earth but second on the heaven.
I also came twice in a week but found just once in a year.
I stay away from months but you can find me in February.

What am I?

How can you write nineteen in a manner that if we take out one, it becomes twenty?

What can run but never walk, have a mouth that never speaks, have a head that never weeps, and have a bed but never sleeps?

I am beautiful, up in the sky. I am magical, yet I cannot fly. To people I bring luck, and to some people, riches. The boy at my end does whatever he wishes. 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?