Here are my tips for improving Quant. I caveat the following by saying that this advice is directed towards someone who is already scoring in the mid-40s in Quant, and may not be generally applicable to people just starting their GMAT studying or who are struggling to reach the mid-40s in Quant.
1. Study deep, not wide: many study materials include a wide range of subjects that you're unlikely to see on the actual GMAT. For example, many materials have whole chapters on combinatorics and advanced probability questions, but you're unlikely to see more than one of those questions on test day. I got a Q49 and saw one such question, and it was an easy coin-flip question, not one of the hard ones. However, you are likely to see a very large number of number properties and word translation problems. Therefore, your study time is best spent mastering number properties (especially exponents/roots, positive/negative, odds/evens questions) and word translations (especially converting tough WT problems into algebraic equations).
2. Buy the GMAT Club exams: I credit these exams from pushing my score from the Q46 I kept getting on practice exams to the Q49 I got on test day. These tests are really hard, but they are a great way to study complex problems, as well as pick up useful tricks to crack tough problems on test day and/or save time on harder problems. The downside is that they are not adaptive like
MGMAT CATs. On the other hand, nearly every question is already 700+ difficulty level, so in a sense, they are "pre-adapted" for very high scorers, if that makese sense.
All that said, sounds like you're a native English speaker, so I would also focus on improving your Verbal score. As others have mentioned, a 1 point improvement in your Verbal score is worth more points on your overall GMAT score than a 1 point improvement in your Quant score. Frankly, if you want a 760, you'll need to improve your Verbal score. A V40 (your highest score to date) isn't high enough for a 760, especially considering you are unlikely to improve to Q51 caliber in 40 days (no offense at all - Q51 is reserved for true quant geniuses!). So devote some time to Verbal as well. Good resources include
MGMAT SC and CR guides (RC is not very good), Kaplan GMAT 800 book, and others you'll find mentioned repeatedly on this board.
Finally, remember that a 760 is barely distinguishable from a 730 at most schools. Assuming you have a decent undergrad GPA, no school will care whether you have a 730 or a 760, provided your score is sufficiently balanced between Q and V.
Good luck!