Passing mark is 50 for ACCA papers. If you have not studied at all, and you are going there just to guess the answers, you probably would still fail. If you have studied I sufficiently and are those borderline type, then probably some will get the pass, some will get the fail marks.
Writing is actually easier in a sense that you can get "sub-marks" even if your answer is not entirely correct, MCQ means either right or wrong.
ACCA standard is still there otherwise UOL won't even have thought of partnering with ACCA for a potential masters degree for those who have completed ACCA.
CFA Level 1/2 is fully MCQ with only 3options per MCQ and CFA is one of the toughest qualification just with MCQ testing.
Think about it ...