Congrats on a solid verbal score, osdelga! MacFauz has the right idea--there are often approaches to certain questions that can save you time. But I have a feeling that you could improve your score substantially just by allocating your time differently.
I'm sure that you already know this, but your score on the GMAT isn't based on the number of questions you get right--it's all about which questions you get right or wrong. The more difficult questions you see, the higher your score will be. This might sound strange, but if your goal is a 700+ (a 45 on quant would do the trick if you maintain your 40 on verbal), you can miss a ton of hard questions and still achieve your goal. On the GMATPrep, one of my students missed 20 questions, and still scored a 44; it isn't unusual at all to miss 17 or 18 questions, and still score a 45.
The trick is, you can't miss easy questions, especially early in the test. Because the GMAT is path-dependent (is you miss an easy question, you see even more easy questions), a few badly placed errors can really hurt you. On the flip side, if you miss a few really tough questions at the end of the section, that won't do much damage to your score... as long as the questions at the end really are difficult.
So this is just a hunch, but I have a feeling that you might be *too* worried about the time during the GMAT, and you end up making unnecessary mistakes throughout the test. If you know what you're doing on a quant question, make sure that you get it right--spend an extra 10 or 20 seconds re-checking your work. And save some time by guessing on the questions that make your head spin--it just isn't important that you get the toughest ones right, and you can miss a huge number of tough questions without endangering your 700. If you can avoid getting stubborn on the toughest questions, you'll probably have enough time to be more accurate on the easier questions, and you'll have a better shot of getting to the end of the exam.
I'm just going off of a short post, so I could be way off here. I hope this helps. Good luck with your studies!
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