This book is really sucks. Totally 80 pages but actually only 20 pages are valuable. All the other 60 pages are junks. I want to sue them (PMI). They are cheating. I have found all the other PMI book have the exact same problem. They don't provide much content in the book but lots of nonsense. I urge everyone stop buying PMI books. I am planning to send them a letter or an e-mail to protest