The extra time doesn't necessarily help if you aren't taking it in the right way in the first place - and spending 9 minutes on one question is definitely one example of the wrong way. :)
Plenty of people spend way too much time on some questions and they get those questions wrong anyway... because the point is that you spent all that time specifically because you didn't know how to do the problem. If you knew how, you'd never have spent 9 minutes on it right? The problem isn't that you got it wrong. The problem is that you were stubborn and took too long to get it wrong. If you'd gotten it wrong in 3 minutes instead, you'd have had 6 more minutes to spend on other questions that you might actually have been able to get right.
Read this:
http://www.manhattangmat.com/blog/index ... to-win-it/And then this:
http://www.manhattangmat.com/blog/index ... anagement/For the time management article, add 50% to all of the numbers / timeframes given. (So, for quant, you want to average 3m rather than 2m for "regular" time. You want to spend no more than 3m45s on any one question as opposed to 2m30s for "regular" time. Etc.)
You can do it - but just be aware that, like everyone else, you can spend too long on problems or have other timing issues even though you have all this "extra" time. (I put extra in quotes because, if you qualify for extra time, it isn't really "extra" for you. You need that time for some very good reason.)
The other thing you should note: adding 50% to the time makes a long test even longer, so you may have mental fatigue and stamina problems as well. That's something to pay attention to as you study - you may have to give yourself "mini-breaks" in the middle of a section, where you decide to give up immediately on what looks like a hard problem, and take 2 minutes to close your eyes and clear your mind, then guess and move on to the next problem.