What you cannot hold but it is yours?

How many triangles can you count in the figure given?

The person who makes it has no need for it. He who purchases it does not use it. The person who does use it does not know they are. What is it?

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

What number divided by 4 is the same as that number minus 4?

As we know that white starts the game of chess. Can you find the scenario shown in the picture below is possible when all the white pieces are at the original place while the black pawn is not as in the below picture?

Who has married many women but was never married?

This is a famous paradox which has caused a great deal of argument and disbelief from many who cannot accept the correct answer. Four balls are placed in a hat. One is white, one is blue and the other two are red. The bag is shaken and someone draws two balls from the hat. He looks at the two balls and announces that at least one of them is red. What are the chances that the other ball he has drawn out is also red?

A word I know,
Six letters contain,
Subtract just one,
And twelve is what remains.

Your last good ping-pong ball fell into a narrow metal pipe embedded one foot deep in concrete.
How can you get it out undamaged, if all the tools you have are your tennis paddle, shoe laces, and plastic water bottle, which does not fit into the pipe?