GMAT Math/Quant: When to write down the info from Q?

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Hello.

My question is when should we start writing down info from the Q? Right away when we are reading the first time? I do this method, but I have realized that this MIGHT enforce you to think in particular/narrow way - the same way in which you have noted the info. For example, best or only way to solve a certain question might be through prime factorization, but we might end up solving by algebraic equations. Other thing is that it might consume lot of time.

So I am confused, and not sure.

Any input?
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by [email protected] » Sat Mar 21, 2015 6:39 am
Hi towerSpider,

To a certain degree, I'd say that this is matter of personal preference.
I take CERTAIN notes because I've identified one of my weaknesses as not paying attention/forgetting certain types of key information.

For example, a data sufficiency target question may ask "What is the value of positive integer x?"
And statement 1 may read: (x - 1)(2x - 1) = 0 [so, statement 1 tells us that x = 1 OR x = 0.5]
If I forget the part about x being an integer, I'll incorrectly conclude that statement 1 is not sufficient, when it clearly is sufficient. So, I'll note this fact on my noteboard.

I also like the idea of taking certain summarizing notes so that you can avoid rereading the entire question later on.

I don't think this will necessarily enforce a particular/narrow view. If you have an approach in mind for a question, that's great. HOWEVER, as you're solving the question, you should always be assessing how much progress you're making so that you don't waste too much time. If you aren't making any headway, you may need to abandon that approach, and start again.

If you're interested, we have a free video on taking notes: https://www.gmatprepnow.com/module/gmat- ... cy?id=1099

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Brent
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by [email protected] » Sat Mar 21, 2015 9:21 am
Hi towerSpider,

Two of the big causes behind pacing problems are:

1) Reading the prompt over and over
2) Getting into the "middle" of solving a question, then realizing you can't remember the 'goal', so you have to go back, reread the prompt and skim through all of your prior work.

By taking reasonable notes while you're reading, you'll likely be able to avoid both of these issues (at least most of the time).

If you have a 'biased' view about how you should approach a question, then that's not necessarily a bad thing, but you probably need more practice (to build up your skills using other tactics).

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by ReasonGMAT » Tue Mar 24, 2015 1:39 pm
Obviously people will have different opinions on this, but especially in the case of PS questions, I strongly recommend that you DO NOT write information down while you are reading the question for the exact reason that you mention: it usually biases you towards a particular approach and while you are writing you are not thinking and brainstorming how to attack the question. If you start translating words into equations as you read, guess what you are going to do on that question? Algebra, obviously, but that may not be the best way to attack the question. You can always write things down on a second pass through the question, but on the first pass, give yourself a chance to digest it and think about how you want to attack the question. The extra time that you may spend doing so will pay off big time in the end if you find a clever way to attack the question (or better yet realize that you have no idea how to do the question and just guess strategically without wasting too much time)!
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by [email protected] » Tue Mar 24, 2015 2:40 pm
This partly depends on the question.

To do some questions, there is no need to write anything down. For instance when doing some DS questions, one can quickly see the answer by using simple numbers that one can easily manipulate in one's head.

For many questions, it makes sense to read the entire question and assess what's going on, and then go back and write down anything that's necessary for calculating the answer.

I could see in certain cases writing things down as one goes through the prompt.

I for one do maybe 80-90 percent of quant in my head, occasionally picking up a pen when I see a question that looks as if it's going to require a fair amount of calculation or manipulation.

The bottom line is that everyone has his or her own style and every question is different. So if you really want to do this optimally you need to get some insights and figure out what works for you and not try to adhere to someone else's formula or to use the same approach for every question.
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by ReasonGMAT » Tue Mar 24, 2015 8:17 pm
Agreed that it depends a bit on the question....and agreed that each person needs to find what works for them.....but in general on PS questions I often see people writing things down before they have finished reading the question and that type of approach almost never works for the aforementioned reasons. The questions are really about problem solving more than they are about Math so people need to give themselves a chance to actually problem solve before they knee-jerk into an approach that they haven't even thought about. Its hard to know what you are going to do before you even know what the question is asking.

On DS I think things are a little different because many people suffer from information overload on those questions and some people need to develop a fixed approach of writing a few things down right away as they take stock of the question (such as restrictions imposed, whether the question is value or yes/no, etc.). That is definitely helpful for some people.

But for PS questions that is almost never a good approach (unless maybe you are scoring in the mid to high 700's on the test and already know what to do on most questions before you have even finished reading them). I mean, I can read a question and know it is an overlapping sets question before I have finished reading it, but I don't think most test takers are in that position and even in that case I would still think about what I was going to do before just diving right in.
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by [email protected] » Tue Mar 24, 2015 8:39 pm
ReasonGMAT wrote:..... in general on PS questions I often see people writing things down before they have finished reading the question and that type of approach almost never works for the aforementioned reasons.
It might help students if you provided an example of this.

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by ReasonGMAT » Wed Mar 25, 2015 9:14 am
Sure, good idea.

The first question that comes to mind is one that I do with pretty much every person I tutor and it is usually one of the first ones I do in part because it gives me a good sense for how they approach questions and gets to the heart of the issue here (about immediately copying information from the question stem). The question is:

If x>0, then x/50 + x/25 is what percent of x?

A) 6%
B) 25%
C) 60%
D) 75%
E) 90%

Many people when they see this question immediately copy down the fractions and then begin to try to add them (most are able to do that without too much difficulty, though I have had plenty of students who are not). People who are at the higher levels are then usually able to solve it from there, but people who are less comfortable with fractions and percents often get stuck. Some muscle through and get to the answer but many do not and people usually spend more time on the question than they need to. However, occasionally I get a student who looks at the question, thinks about it for a bit, and then realizes that they can pick numbers - and if they think carefully enough about what number to pick then the question can be answered in literally 10 seconds without even writing anything down. When I see a student like that I usually know I am dealing with someone who is going to do well on the GMAT. If you pick a number that gets rid of the fraction entirely (such as 100) then in your head you can probably say 100/50 is 2, 100/25 is 4, and 2 +4 is 6. 6 is obviously 6% of 100 so the answer is A.

People who first copy down the fractions as they are written in the question almost never see this option because they have already biased themselves in an algebraic direction before they have even considered whether that is the right approach for them. Obviously that is the right approach for some people so I am not saying that everyone should pick numbers on this question, but in my opinion you really need to give yourself a chance to very open-mindedly consider your options before writing anything down because as you are writing you are not really thinking and once you have the information written down you may find that you are sort of unwittingly pulled in a certain direction.

I also coach people to look at the answer choices before writing anything down as well, because often the answer choices provide clues as to how to solve the question. The above question is not the best example, but the answer choices are spread fairly widely apart, so if a person were to consider the algebraic option on this question and think that they weren't sure how to do it, and if they couldn't think of any other way to attack the question, they could try to think of the question conceptually and make a guess (because with the answers spread apart as far as they are it may be possible to guess very effectively on this question). If you think about is x/50 means x divided by 50, so that is a very small fraction of x. Likewise, x/25 is obviously a very small fraction of x. So if you were to add those quantities together they would still represent a very small fraction or very small percent of x. Looking at the answers even 25% seems like it would be too high, so 6% would be a very good guess on this question. In my experience, someone who immediately copies down the information from the question is very, very unlikely to head down this path.

Again I am really talking more about PS questions here. I recommend a similar strategy for DS, but because DS questions often give you so much information to keep track of and because some people get overwhelmed and lost in taking stock of all of that information, for some people I think it is a good idea to write SOME information down (value vs. Y/N question, restrictions imposed, etc.) right away. And again obviously there may be some PS questions for which writing information down as you read would be a good idea (and perhaps for people who have particular difficulties maybe it would be called for), but I would honestly be hard-pressed to think of a GMAT PS question where I would suggest that the general GMAT-taker write information down as they read.
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by towerSpider » Thu Mar 26, 2015 9:37 pm
ReasonGMAT, nice post.
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by ReasonGMAT » Fri Mar 27, 2015 3:14 am
Thanks brother (or sister). Hope it helps!
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