I was just trying to say that even if you are able to solve SC questions with 80% accuracy.....that is great but will not ensure that you get 720 in real GMAT.
Hence, the true evaluator should be the score in mock tests like
GMATPrep.
Quant score of 48 and Verbal score of 40 can give you 720.....that would mean (approx 10 questions incorrect in both sections).
Use mock tests to evaluate yourself instead of individual areas-questions in
OG.