Hello Lukasz,
If you are referring to the PrepCast Exam Simulator, I have tried all exams and my highest score was 78% with an average of around 75% for all 4 exams. Based on your scores I would say you're probably ready for the real exam. For you to get the scores that you got, it shows that you understand the concepts and that you probably studied enough using other resources. Let me know if I'm on the right track, but I would never recommend the exam simulator as your only study resource. I would also review the PMBOK guide 7th Ed, the Agile Practice Guide, and of course the PrepCast. Hope you have used some of these.
All the best!
P.S. You have a duplicate post, so I deleted the other one.