It's a myth that you need at least 61% to pass the PMP Certification Exam. Well, this might have been partially true till 2005 but not anymore. There is no fixed score to clear the PMP® exam. Some experts say the PMP exam pass rate is less than 70%.
The marks you obtain will be based on the difficulty level of the questions you get. PMI follows such a format because the PMP® certification exam is a psychometric test.
In this, no two candidates get the same set of questions nor all the questions carry equal weightage. If you get a questionnaire with easy questions, then the passing score is likely to be higher for you. Similarly, if you get difficult questions, then the passing score will be much lower. Know how to pass PMP in 10 days here.