Give this puzzle a try. It's well worth it if you haven't done it before. Once you have gone through it, think about it hard and apply it to everything you see.
Here is how it works. Read and answer the questions in the above slide. You can move forward by clicking on the image.
CRITICAL NOTE: Make sure you solve every single problem presented before you click next to see the solution. If you don't follow this, the puzzle may not make sense to you and it will be spoiled.
Did I mention you should not skip a problem ....
You can download the Power Point source file from here.