TOPIC: I don't know where is the mistake

I've entered PMP exam 3 times but I didn't pass. I don't know where is the shortage from my side. I did everything possible for this exam.

I read PMP book 3 times, I get PMP study book for Kim Heldman (it is good book by the way), I watch prepcast videos 2 times, I solved more than 2000 sample questions on all knowledge area, I solve 6 simulated exams 4 of them from PMSTUDY.com and my average score was 77% in these exams.

I don't know what else I've to do, I think I did everything possible to pass the exam but I didn't pass, please advise.

I would highly recommend taking a PMP Prep course either online or at your nearest college. SOmetimes it takes another form of learning to help everything make sense.