Hi meeh1872,
3 weeks is not a lot of additional study time, but you could potentially make some meaningful improvements and raise your score. Many Business Schools place a greater emphasis on an applicant's Quant Scaled Score (since that score is often seen as a 'measure' of an applicant's ability to handle the 'academic side' of the Program), so I would suggest that you focus on that portion of the GMAT. With a Quant Scaled Score in the low-40s, you're pretty good at most of the 'math' questions that you face, but you're making little mistakes throughout the Quant section and you're missing out on LOTS of 'strategy-based' points. If you continue to practice in the same ways as before - and answer Quant questions in the same ways as before - then you will likely continue to score at the same level. As such, your focus has to shift towards learning and practicing the proper Quant Tactics. Whether 3 weeks is enough time for you to incorporate all of those ideas or not is the question.
Based on everything that you've described, I think that you would find the EMPOWERgmat Quant Score Booster to be quite helpful. Most of our clients complete that Study Plan in under a month, so it should fit your limited timeframe. We have a variety of free resources on our site (
www.empowergmat.com), so you can 'test out' the Course before setting up an account.
If you have any additional questions, then you can feel free to contact me directly.
GMAT assassins aren't born, they're made,
Rich