Ramesh, studying for the PMP exam is time-consuming. It is important to give yourself enough time to study all the materials and take practice exams. Depending on how much time you can devote to daily studying, expect to spend at least 6 weeks preparing for the exam, and most likely more than that. I studied for 3 months (using Rita's book and the PMBOK along with the exam simulator) prior to sitting for my exam. It was definitely worth my time to read both books.