As an Engineers and Applied Physicist we have to start thing about your question. Im new here. I don't know much about CSS exams . I have done my Masters in 2009. And now I'm thinking to appear in CSS. I have many options.
The system we are living is in influence from many other systems and surroundings. When this happens it cause only noise and when there's is a lot of noise ,there's nothing transparent. In order to make it noise free we have get rid of Traps(Corrupt politicians, Making security departments transparent and to do more and more it needs)....