The written test is based on Chapters two and three, again, from the manual. It's a 20-question test. You have to get 14 questions correct in order to pass it. The basic tip for that is to just read the manual, become real familiar with the information in each chapter. At the end of each chapter you've got some sample questions, and the sample questions give you an idea of whether or not, of course, you know the subject matter. I would pay attention to Chapter nine in the book. That's the chapter on drugs and alcohol. Real good information in that chapter, as far as knowledge on the subject matter. Usually about five of those 20 questions will come from that chapter, so it's a good idea to become real familiar with Chapter nine. Again, read the manual, become real familiar with Parts two and three. Your written test comes from those parts. Remember, 14 out of 20 is what you need in order to pass. Good luck with that.