Hey Gurpinder,
Good question...and unfortunately it's one that doesn't have an easy answer. Your score is calculated using the following factors:
-Number of questions answered correctly
-The difficulty level of those questions
-Number of questions answered overall (with severe penalties for leaving several questions unanswered)
Because of that difficulty level factor - which is a big one on a Computer Adaptive Test - your number correct doesn't give a terrific correlation to your scaled score. For simplicity's sake, let's just look at ten questions and assume that you start at a 50th percentile level. You could get 5 out of 10 correct in multiple ways, including:
Wrong, Wrong, Right, Wrong, Right, Wrong, Right, Wrong, Right, Right
Here, you'd have to think that by getting the first two wrong and then never getting consecutive right answers until the very end you probably stayed lower on the difficulty scale, so your 5/10 would still correspond to a slightly less-than-average score.
You could also go:
Right, Right, Wrong, Right, Wrong, Right, Wrong, Right, Wrong, Wrong
Here, it would seem that your first few right answers would have you at a higher difficulty level, so your correct answers would build you more points and the wrong answers wouldn't hurt you as much, so that 5/10 would probably yield a higher score.
NOTE: This is an intentionally crude demonstration - the GMAT has 37 and 41 questions for its adaptivity to work, so don't think that you HAVE TO get the first two right to get a good score or that getting the first two wrong dooms you. This is just a quick demo!
You may want to check out this blog post on the scoring algorithm, which links to a study conducted by Akil over at BellCurves in which he breaks down test results to show that you can get the same scaled score with wildly different numbers of right/wrong answers:
https://blog.veritasprep.com/2010/08/und ... rithm.html
The best advice I can give you - spend the vast, vast majority of your time working on getting questions right and you won't have to worry about the way it's scored. It's much easier to score well by doing well than by trying to game the system!