The 75 score is not a percentage correct, that's what they say.
The thing is how is the 75 score determined, in light of the pretest questions which do not count for your score?
NOTE: This is my opinion, this is not something the AICPA may confirm.
Six sims, one doesn't count. So five only count for your score.
3 WC's for BEC only – one doesn't count. So only two counts for your score.
72-90 MCQ's. 25% are pretest. So 54 to 68 count for your score.
Take the above and add it all up, if you get 75% of what counts….I think that is the score.
So if you get a 75% correct on your total exam, you'll get a 99 score only if 100% of wrong answers were pretests.
You COULD pass the exam with less than 75% correct if most of your wrong answers are pretests. Or you can get all the pretests right and still fail. That's the random element to the exam.