When preparing for the GMAT you will often hear people say that you should spend 2 minutes per question on Quant questions, yet this advice is misleading and I have seen it hurt many test takers. Of course with 45 minutes and 21 questions you do have on average roughly 2 minutes per question, but that does not mean that should aim to spend 2 minutes on each question.
This flaw is usually based on 2 misunderstandings, in my opinion.
First of all, people have a misunderstanding of how many questions they need to get right on the Quant section in order to have a high Quant score. Now, if you are aiming for a near perfect Quant score then indeed you need to have almost every question right. But if you are aiming for a top, though not perfect, Quant score, then you can probably have between a third and a half of the questions wrong, provided of course that you are seeing hard questions throughout the section and getting many of those questions right as well. So when they think that they need to get virtually every question right, people tend to want to distribute their time equally across all questions. Again, this strategy is based on the flawed assumption that you need to get almost every question right. Given that most test takers are likely to get about half of the Quant questions wrong, including people at the top of the Quant scale, it obviously doesn’t make sense to spend undue time on questions that you are likely to get wrong anyway. One of the worst things that can happen on the test is to spend 5 minutes on a question and then get it wrong!
This leads to the second realization, which is that not all questions require an equal amount of time. First of all, some questions will be relatively easy and can be done in a minute or less (this is even true for high scorers….in my own GMAT attempts, one thing that was obvious to me was that I was definitely seeing some Quant questions that were not that hard). But other questions genuinely require more than 2 minutes and if you have an internal 2 minute timer going on every question, like many test takers do, you are never going to be able to answer some of those harder questions. So some questions are worth spending 3 or 4 minutes on, provided that you think you have a very good chance of answering them correctly with the extra time.
Now, what do you do if you need 3 or 4 minutes on a lot of questions but don’t have that many questions that you can answer in 1 minute or less. Well then you need to guess on a certain number of questions and the goal is to try to figure out when you see a question whether it is one that you are likely to be able to answer correctly in a reasonable amount of time or not. Consider this thought experiment: What if you were capable of answer most hard questions correctly but you needed more like 3 minutes on each question? Well if you limit yourself to 2 minutes per question you are going to get most of those questions wrong. If, theoretically, you could throw away every 3rd question very quickly and just spend 3 minutes on each of the other questions, you would get 2/3 of the questions correct and you would finish on time. Of course it takes some time to decide whether a question is worth your while or not and you are not always going to get the questions right that you don’t throw away, but on the flip side you may be able to guess really well on the one’s that you do throw away and get some of those right as well!
The point is that guessing is a part of the GMAT and should be part of your strategy, especially on the Quant section. Anecdotally, the first time I took my GMAT I got a 760, but I knew that I had time management issues, so I went into the test expecting to guess on at least 3 or 4 questions (not because I couldn’t answer them, necessarily, but because I knew that they would take me a long time and that I needed to make up time somewhere). So when I started to fall behind on time, I would go into what I call “Shark Mode.” I would basically hunt for an opportunity to let go of a question and guess in the interest of gaining back some time. So I would be on the lookout for a really hard question that I also thought I could make a pretty good educated guess on in a very short amount of time. It was really a shift in attitude such that guessing was not an act of defeat but an act of self-preservation. And if you consider that most GMATer probably don’t do this, you very likely give yourself a big advantage over other test takers when you do!
So if time management is an issue for you, as it is for most test takers, remember that some questions genuinely do require more than 2 minutes per question and part of being successful on the GMAT is knowing how to decide whether a question is worth your time (even if takes 3 or 4 minutes to solve) or whether it would be better to quickly let go of the question and make a quick, educated guess.