Be active and find the killer in the picture Riddle below.

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?

What do you think with the below Picture ?

Find the next number in the sequence

1, 2, 6, 21, 88, __?

In the given figure, move three matchsticks so that the resulting figure contains two rectangles.

You can see it everyday, But cannot touch it at will. What is it?

No matter how little or how much you use me, you change me every month. What am I?

Three people enter a room and have a green or blue hat placed on their heads. They cannot see their own hat but can see the other hats.
The colour of each hat is purely random. They could all be green, blue, or any combination of green and blue.
They need to guess their own hat colour by writing it on a piece of paper, or they can write 'pass'.
They cannot communicate with each other in any way once the game starts. But they can have a strategy meeting before the game.
If at least one of them guesses correctly they win $10,000 each, but if anyone guesses incorrectly they all get nothing.
What is the best strategy?

Where do fish keep their money?

Who can jump higher than a Mountain?