Advice - 6th Edition Manhattan Prep and Quant Section

You don't need to limit yourself to 2 minutes for each problem. The 2 minute figure is an average - if you can finish (or guess on) one problem within 1 minute, you've got an extra minute to spend wherever you like. And to be honest, some problems are very tough to finish within 2 minutes even if you know exactly how to solve them (for instance, lengthy word problems that involve a lot of reading time.) So that's part of the story: focus more on finishing 5 problems in 10 minutes, than 1 problem in 2 minutes.

It's okay to sometimes work without a timer - for instance, when you're first studying a brand new area. But please continue to use a timer as much as you can manage while studying, even if it's frustrating for the time being. The justification for this is that the GMAT is hard because it's a "pressured" test, meaning that most test-takers, in theory, would be able to solve a very large percentage of the questions if they were given unlimited time. It's the added time factor that distinguishes people who get high scores from people who get so-so scores: even if both people could answer the exact same questions, the person who can do it more efficiently should be given a higher score. So if you work without a timer, you're fundamentally practicing a different skill set from the skills you'll need on test day.

However - that only applies the first time you try a problem. When you've finished a problem, go back and do it again with no timer!! And then do the same a week or two later, and then a month later! And as you do this, think about more efficient and faster ways you might solve it. If you don't do this, you'll just keep beating your head against the same wall of being unable to finish problems within the time limit. But if you review and think specifically about being more efficient, your timing will be just that little bit better next time...