I don't think so that it is possible to convert the number of correct questions into actual GMAT score as the GMAT Score depends on a lot of thing. Some of them are:--
1. The difficulty level of the correct/wrong questions.
2. Whether there are consecutive right/wrong answers.
3. How was the performance in first 10 and last 10 questions of each section(Quant and Verbal i mean)
4. How many and of what difficulty level RC questions were marked as right/wrong
and a lot many factors! SO i doubt if you can convert the number of right/wrong answers to an actual score just like that!
Hope it helps!
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