Hey,
Congrats on the great score. As you can already see, the score is already amazing but has a narrow scope of improvement too, especially Quant. Getting 50 or 51 on quant should not be difficult for you after a week's of practice. For verbal, you can look for the areas where you don't feel confident or weakness areas, and try to enhance by 3-4 points there.
As for your question, the number of correct questions does not drive the score but what matters is which ones you get right. Getting one 700-level question wrong has a different impact than getting one 500-level wrong. Further, if you get too many wrongs, it often becomes difficult to even get those 700-level questions in the first place because of the adaptive nature of the exam.
As per the interpretation of the scores, the scores are just indicative of how have you fared in the exam. The associated percentile can give you a better picture of where you stand.
Hope this helps.
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