Hi there,
There are many possible combinations of quant and verbal scores that will yield a 600 or higher. If you are fairly balanced between quant and verbal, you might aim for a 40 or higher in quant and a 33 or higher in verbal. Although that verbal score seems much lower, it actually represents a higher percentile score than the 40 in quant, in part because there is more competition on the quant side. Note that these are on the low end--to be safe, you would want to aim somewhat higher. Naturally, if you are much stronger in one subject, you can underperform on the other, although some schools may consider your subscores in addition to your overall test score.
As to the number correct, because the GMAT is a computer adaptive test, it's not possible to predict a score based on the number correct/incorrect. Most test-takers will miss about 40% of the questions. Naturally, it's great (but practically impossible) to get all the questions right, and it's not so great (and also fairly difficult) to miss them all. However, two people with the same number of missed problems might have drastically different scores, depending on *which* problems they missed. You get rewarded more for getting hard problems right, and penalized more for missing easy problems. You also get *no* credit for answering experimental questions correctly, and you won't know which these are. You will also receive an additional penalty for timing out at the end and leaving questions unanswered.
So what's the best response to all of this? See how close you are to your score goal, and then work on improving your content knowledge, problem-solving process, and time management. Don't worry so much about the number of problems you are getting right, especially since this is something you can't directly control. Just focus on getting more problems correct without overinvesting time and effort on any one problem. If a problem is too tough to do in 2 minutes, let it go!
I hope this helps. Let me know if I can shed any more light on your specific situation. Good luck!
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