The passing score on the PMI PMP exam is a closely held secret. If it is like other professional exams that I have taken, the passing score will change slightly between individual exam, based on the test questions that come out of the pool.
Each exam question has only one right answer (out of four possible answers) and your are not penalized for guessing.
Training for Project Management Professional (PMP)®, PMI Agile Certified Practitioner (PMI-ACP)®, and Certified Associate in Project Management (CAPM)®