PMP Certification Exam Structure
PMP Exam is designed to test real Project Management Experience and Knowledge Areas defined in PMBOK Guide. Just PM experience or mugging up PMBOK guide is not sufficient. One should really have combination of both. Real time experience and patience to read wordy questions and conveying knowledge to situation questions are key qualities to pass the exam.
Exam constitutes of 200 multiple choice questions. Each question will have 4 multiple choice answers to choose. Out of those 200 questions 25 questions are “Pre-Release” questions. PMI will not mark those questions. But aspirant will not know which one is which. So the real exam is of 175 questions. Out of which 61% is pass mark. That means approximately Aspirant should get 106 right answers.
Questions can be classified across Phases of the Project. (I deliberately used the word “Phases”. In PMI terminology it is “Process Groups”). Following figures explains a little bit more:

If you are working in any of current corporate environments you should have done "Corporate Ethics" Course. Or you can get that book from you HR. Those Ethics closely matchs Project Managment Ethics.
Just knowing all 44 processes and inputs, outputs, and tools can get you some 20 answers right.
Basic Project experiance can get you some 20 answers.
Which means you are half done in the exam. Industry experts and surveys shows that 40-60 hours of preparation is required for the exam.