Count the number of balls in picture below:

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?

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

If you had a pizza with crust thickness 'a' and radius 'z', what's the volume of the pizza?

Find the next number in the series

12, 20, 40, 72, 116, 172 ?

I am an eight letter word and I am a computer terminology.
The second, third and fourth letters make an animal.
The fourth, fifth, sixth, seventh and eighth letters make a weapon.
The first, second, third and fourth letters can be taken as an outcome of any exam.
The fifth, sixth, seventh and eighth letter combine to form a high end typing software.

Can you tell who am I ?

What does this below rebus puzzle mean?

A seven-year-old kid challenged his classmates that he can make the number one disappear by adding something to it.

How can he do that?

Why is it against the law for a man living in Delhi to be buried in Mumbai?

Can you find the key in the picture below?