## Strategies for preventing careless mistakes ...

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### Strategies for preventing careless mistakes ...

by II » Mon Aug 25, 2008 3:51 am
I have been seeing a common pattern to my mistakes on practice tests and practice OG questions: Making simple careless mistakes !

Making simple careless mistakes is what is letting me down at the moment. I believe I have a fairly good grasp of all the concepts in Quant ... but in practice tests or when I am doing practice questions in timed mode ... the questions I get wrong tend to be due to careless mistakes on some of the simpler problems !

Consider an example:
OG Quant DS question 31 (this is a very simple question). I correctly identify that I need to find the amount of work (capacity of pool) and the filling rate in order to find out how long it will take to fill the pool. Time = Work/Rate.
(1) provides me with the rate, but not the capacity. So INSUFF.
(2) provides me with the length and width of the pool. In my working I incorrectly assumed that this provides enough info for calculating capacity from the length and width, but still it didnt provide rate info. so insuff.
(1) and (2) together: I incorrectly assumed that I have the rate from (1) and the capacity from (2). Note: (2) Doesnt provide the depth which is required to find the true capacity of the pool ! So I guess I fell into the trap set by the GMAT here. I chose C, where as answer was E here.

What concerns me is that I understand the Quant concepts, and was going about answering the question in the right way ... I messed up with statement 2, thinking that I had enough info to calculate the capacity.

I suppose one way to go about this is to actually write things down on the scrap paper.
For example at the start of the Question write down Capacity = length*width*depth. So when I come to statement (2), I clearly know what I need to calculate the capacity, and can easily see (2) doesnt provide sufficient info to calculate this.

The GMAT test is designed to pick out holes in your knowledge ... so if you are making simple careless mistakes on 500-600 level type questions, then you see zero or very few 600+ level questions limiting your ability to score in the 600+ range.
Would appreciate some feedback on how others are dealing with eradicating silly careless mistakes such as these.

II

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by codesnooker » Mon Aug 25, 2008 5:04 am
Hello II

I don't how much its going to help you. Once I was also at the same situation (though partially), in which currently you are. I was scoring around 47-48 in the practice test. I did following four things and it boosted my score up to 50 (quant) in the real GMAT.

1. Do the open drill, a week before your real GMAT (I did this a night before the GMAT). As in one of the post, Ron stated that open drill is to know the starting point of each and every question of quant. It means during test when you see the question, you should know how to start it without even thinking the solution at that moment. So, a week before your test, go once through at least last 50 questions of quant of OG 11 from each section. Just learn how to start them, if you don't have time to practice them completely.

BENEFIT: It will prevent you from panic of UNKNOWN in the real exam and also increase your speed of doing the questions.

2. Try to identify the pattern of the question, especially in DS. I believe that for 90% of DS question, one does not need to pick the pen and can be solved in mind itself. But it does need lots of practice to identify the patterns of trap in DS questions. I did the same. If you do not started this yet and your exam is nearby then I think you should skip this approach. As without practice, it may result oppositely and you may loose more score. Do this if you enough confidence.

3. During the real exam, after deriving the answer, once again read the question and check what author has demanded to derive. And then check your answer. I am 100% sure that it will save your at least 3-4 question from getting wrong. During my exam, I was half sleepy during the exam (because of mine wrong sleeping pattern), and I followed this technique and it saved my 3-4 mistakes in the first 15 questions. I hope you know that getting first 10-15 questions right is very important to score high. Believe me its do able. Even after following this, in real GMAT, for me, 5 minutes remained at the last question of Quant.

4. Watch the clock and in any case, do not spend more than 4 minutes to any question. If you confused during the exam and the question taking too much time, then make a educated guess and move on. But to do this one need to be courageous to do so. Absolute inequalities is my weakest area in DS. And I followed this technique in ream GMAT for two such questions.

The above techniques worked for me. But they require clear concepts of quant and high solving speed (because third technique is time consuming for those who are slow in Quant). So if you want to use them, use wisely.

Rest you can better judge your condition on own.

Best of Luck,
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by II » Mon Aug 25, 2008 5:59 am
Hey Codesnooker ... thanks for the response man. Some good tips there !

(1) I am pretty much already doing this. My test is on Friday, and over the next days I am spending all my time on the practice questions and reviewing them. I agree it is key to be able to categorise a problem pretty much immediately and identify the strategy/approach for solving.

(2) I am finding with DS that I am doing a lot less writing on the scrap paper than when doing PS questions ... since all you have to do is determine if you have sufficient info to answer the question ... you dont have to get the final answer. Also I am finding that the rule "number of unknowns has to match the number of distinct equations" helps a lot here.
I think I am beginning to get an idea of the types of traps that GMAT tries to throw into DS questions ... and how it attempts to confuse you by providing conflicting information.

(3) This is a good point ... and not something I have been doing so far. The only thing is that you have to balance this with time management ... but I think a quick check to verify whether you have actually answered the question can help.
I also think that it is important to develop ability to extract the useful pieces of information from a question and write this down on the scrap paper. GMAT sometimes provides you with extra information which is sometimes not relevant to answering the question ... just to add to the confusion/complexity.

(4) Timing ... I have never spent anywhere near 4 minutes on a question ... my absolute max has been 3 minutes. But I think developing an ability to decide on which questions to persevere with and which ones to let go is key. So if I have spent nearly 2 minutes on a question, and I know that I am close to the answer, then I will take the extra time to do it. If I spend 90 seconds on a question and I am no closer to the answer, then I spend the remaining 30 seconds trying to make an educated guess and then move on.
I find that I tend to spend more time on the word translation type question (algebraic translations, ratios, rates and work) ...

I think as well as your ability to do Quant ... the GMAT is testing your ability to comprehend information in a pressurised/stressful environment.

P.S. Also I am trying to ensure that I build a solid foundation for my test ... I should be able to answer the full breadth of problem types (Word Tran, Ratios, Rates, Averages, Geometry, ... etc) in the 300-600 range without any difficulty ... and ensure I dont make careless mistakes.
Any mistakes when answering these types of questions will not enable me to get onto questions which are 600+ level, and hence prevent me from getting my target 600+ score for my first attempt.
Once I have built a solid foundation at the 300-600 level (confidently being able to answer these questions quickly and accurately), then I can start doing the same for the 600+ level questions.

Thanks ... any further input to this topic is appreciate. Any tips on preventing careless mistakes ...

II.

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by codesnooker » Mon Aug 25, 2008 6:36 am
To prevent careless mistake you need to follow the third point as I mentioned in my previous post.

Another thing
II wrote: (2) I am finding with DS that I am doing a lot less writing on the scrap paper than when doing PS questions ... since all you have to do is determine if you have sufficient info to answer the question ... you dont have to get the final answer. Also I am finding that the rule "number of unknowns has to match the number of distinct equations" helps a lot here.
I think I am beginning to get an idea of the types of traps that GMAT tries to throw into DS questions ... and how it attempts to confuse you by providing conflicting information.
The example of DS question you stated above (for number of unknowns), there is very common and familiar trap in such questions. Hope you know the trap. Anyway, I mentioned here also for other's benefit.

In number of unknowns problem of DS, usually the questions solved on checking the number of unknown to number of equations available. But if you are doing good in the test then GMAT often use to give question in which statement (1) correctly works on this formula. However, statement (2) also looks like to work because if you merely look on the equations, you will find that the number of equations are equal to number of unknowns, therefore you will hit choice (C) as your answer, but here is the GMAT trap. If you resolve the equation evolved from statement (2) then you will find that it will reduced either to the equation evolved from statement (1) or given statement in the question.

In short, the question looks like that the equations from both statements will lead to resolve the two unknown parameters, however, both in real scenario, both statements are same. Just one of the statement is multiplied with bigger number. So, in such cases, usually answer is (E) instead of (C).

This is very pretty familiar and easy trap of GMAT, in which people usually fall. So always reduced the equations to the least coefficients of the one of the unknown variable.

II wrote: (3) This is a good point ... and not something I have been doing so far. The only thing is that you have to balance this with time management ... but I think a quick check to verify whether you have actually answered the question can help.
I also think that it is important to develop ability to extract the useful pieces of information from a question and write this down on the scrap paper. GMAT sometimes provides you with extra information which is sometimes not relevant to answering the question ... just to add to the confusion/complexity.
II.
I will try to give example of careless mistake. For example, in compound interest question, you were asked to find the total amount paid after 1 year, compounded semi-annually. People know how to find the CI, but the mistake people usually do (due to carelessness), after finding the CI, they checked the given choices, they find one of the answer matching to CI, they hurriedly hit that choice thinking that as the correct answer. But did author asked for CI? No, he asked for total amount, i.e., CI + principal amount. But usually we are so much enthusiastic during the test, we usually forget what exactly need to find, and in the mid-way only we hit the answer (though it happens only in 3-5 questions). So, in this way, though we know the formula/concept/answer of the question, but due to carelessness, we lose that question.

So my suggestion is, after finding the answer, re-read the question once again (with full-heart, don't assume that you already know what you have to find, because I usually skip the rereading of question with thinking that I already what I need to find) and then check again your answer. After that only mark the answer. But again, as I said, this required speed and concentration.

SHORT CUT TO DS QUESTIONS

Okay there is one shortcut for the DS questions (for those questions, which has correct answer id (D)). I hope you know that. In most of the cases, if you were able to solve the question with statement (1) and on seeing or resolving the statement (2), you lead to a equation that will be same as the equation derived from statement (1). Or vice-versa. So, in such cases, 90% times, the correct answer is (D). But you can follow this, in case, if you are short of time.

Rest seems good to me. If you have any other question, write back, I will try to answer it.

Best of Luck,
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by pepeprepa » Mon Aug 25, 2008 6:42 am
You discussed about many things but something surprised me II.
The fact you don't always write on a paper each question. It perhaps depends on people but it's clear you will diminish the number of careless errors.
I also think you know what type of fool errors you are used to do... just try to take care when you face them the D-day.
Another point is not to fear to be wrong, when you want to check everything, be sure you do not make any fool error... it's dangerous. That's what I felt during my last practice, I did not want to make only one error, I checked 3 times my answer. That's a really wrong method and I won't do it anymore because it steals me useful time for harder questions.

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by II » Mon Aug 25, 2008 6:50 am
codesnooker wrote: The example of DS question you stated above (for number of unknowns), there is very common and familiar trap in such questions. Hope you know the trap. Anyway, I mentioned here also for other's benefit.

In number of unknowns problem of DS, usually the questions solved on checking the number of unknown to number of equations available. But if you are doing good in the test then GMAT often use to give question in which statement (1) correctly works on this formula. However, statement (2) also looks like to work because if you merely look on the equations, you will find that the number of equations are equal to number of unknowns, therefore you will hit choice (C) as your answer, but here is the GMAT trap. If you resolve the equation evolved from statement (2) then you will find that it will reduced either to the equation evolved from statement (1) or given statement in the question.

In short, the question looks like that the equations from both statements will lead to resolve the two unknown parameters, however, both in real scenario, both statements are same. Just one of the statement is multiplied with bigger number. So, in such cases, usually answer is (E) instead of (C).

This is very pretty familiar and easy trap of GMAT, in which people usually fall. So always reduced the equations to the least coefficients of the one of the unknown variable.
Yes ... and that is why I mentioned "DISTINCT" equations. But you make a very good point about highlighting this point. The GMAT does indeed use this as a trap. Key thing is to check that you do in fact have DISTINCT equations. Eg. 2x+4y=8 is the same as x+2y=4. Here you have 2 unknowns and 2 equations ... but the equations are the same. So in this case you DO NOT have sufficient information to solve for x and y.
codesnooker wrote: SHORT CUT TO DS QUESTIONS

Okay there is one shortcut for the DS questions (for those questions, which has correct answer id (D)). I hope you know that. In most of the cases, if you were able to solve the question with statement (1) and on seeing or resolving the statement (2), you lead to a equation that will be same as the equation derived from statement (1). Or vice-versa. So, in such cases, 90% times, the correct answer is (D). But you can follow this, in case, if you are short of time.
Dont think I understand you here. Can you please explain. Thanks.

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by Stacey Koprince » Fri Aug 29, 2008 8:59 am
The more general shortcut with answer choice D is this: if the two statements tell you exactly the same piece of information, no more and no less, then the answer must be either D or E. If you've already decided that one of those statements does work, then the answer must be D.

This applies to equations or anything - if the two statements are ultimately identical, then you're down to either D or E.

Also wanted to comment on something pepeprepa said. I write EVERYthing down in math, because I know I will seriously reduce the number of careless errors I make if I do so. I make a lot more mistakes in my head than I do on paper, and if I make the mistake on paper, I'm a lot more likely to notice the mistake visually. If I make the mistake in my head, there's no "paper trail" and I'm very unlikely to notice the mistake after the fact.

If you write while you think, it doesn't take any extra time to write everything down. Just keep that pen moving constantly!
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by II » Fri Aug 29, 2008 10:53 am
Stacey Koprince wrote:The more general shortcut with answer choice D is this: if the two statements tell you exactly the same piece of information, no more and no less, then the answer must be either D or E. If you've already decided that one of those statements does work, then the answer must be D.

This applies to equations or anything - if the two statements are ultimately identical, then you're down to either D or E.

Also wanted to comment on something pepeprepa said. I write EVERYthing down in math, because I know I will seriously reduce the number of careless errors I make if I do so. I make a lot more mistakes in my head than I do on paper, and if I make the mistake on paper, I'm a lot more likely to notice the mistake visually. If I make the mistake in my head, there's no "paper trail" and I'm very unlikely to notice the mistake after the fact.

If you write while you think, it doesn't take any extra time to write everything down. Just keep that pen moving constantly!
good points ... thanks Stacey

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by lunarpower » Fri Aug 29, 2008 9:25 pm
ok, so this post is independent of the preceding discussion; it's more of a tip for the prevention of "silly mistakes" in general. the following advice is tremendously useful not only on the gmat, but also in life in general:

you can prevent, or at least minimize, ANY kind of silly routine error, just by BEING AWARE OF YOUR TENDENCY TO MAKE THAT ERROR.

analogy:
let's say that you've stubbed your toe on a certain piece of furniture in your living room a few times (and the furniture is situated in such a way that you can't just move it).
are you just going to resign yourself to stubbing your toe every time you walk through that room, declaring that such silly mistakes are just out of your control?
no, of course you aren't. instead, every time you walk through that room, you're going to do so with a heightened awareness of that particular piece of furniture, and - voilà! - no more stubbed toes. yeah, you might hit it once or twice in a few years' worth of walking through that room, but you can bet that you'll NEVER hit it if you've just, say, had toe surgery.
heightened awareness!

now, for the gmat application:
let's say that your test-taking is plagued by 2 distinct types of errors: (1) solving for the wrong quantity, as illustrated in the very first post of this thread, and (2) sign errors (+/-) in algebra.
here's what you do:
just like walking through the aforementioned room, all you have to do is solve the problems with a HEIGHTENED AWARENESS of those two mistakes - and you won't make them. just keep them in your mind as Things To Look Out For - every time, just as you'd think about stubbing your toe every time you walk through the room - and eventually that extra caution will seep into your subconscious. it just will.

if you don't believe me that this sort of self-mind-control stuff works, imagine a hypothetical situation in which you got an automatic 800 on the gmat, no matter what else you did, as long as you didn't make either of those two mistakes a single time.
in that situation, do you think you'd ever make one of those two mistakes?
of course you wouldn't.
proceed accordingly.

good luck.
Last edited by lunarpower on Fri Aug 29, 2008 10:18 pm, edited 1 time in total.
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by lunarpower » Fri Aug 29, 2008 9:43 pm
oh yeah, and one other thing.

almost no one believes me when i first tell them this, but then about 90% of the skeptics come back wide-eyed with astonished declarations of "you were right!":

performing routine processes mentally, rather than on paper, will SLOW YOU DOWN.

the more steps you write down, the FASTER you will execute the process.

this holds for pretty much everything - factoring, AD/BCE, eliminating answers, charting RTD problems, defining variables, etc. about the only exception that comes to mind is VERY simple arithmetic; there's no need to write down, say, addition and subtraction of one- and two-digit numbers. BUT YOU SHOULD WRITE DOWN EVERYTHING ELSE.

the other thing of which you should be aware is that the mental processes will work, most of the time. this is more than a bit ironic: the reason that the vast majority of students don't want to write steps down is that NOT writing them down usually works.
let's say that mental processes get you correct answers 85%, or even 90%, of the time.
what you've got to realize, though, is this: writing down the steps will ensure correct answers 99+% of the time. if you're just working practice problems, that's not that big of a difference - but i wouldn't want to bet gmat points on an 85% or 90% sure thing.

write down everything.
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by II » Fri Aug 29, 2008 11:31 pm
Great input there Ron ... thanks for that !

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### Open drill?

by acerche » Mon Oct 20, 2008 9:00 am
Does anyone know what the "open drill" is that codesnooker refers to in his/her post?

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### Re: Open drill?

by codesnooker » Mon Oct 20, 2008 1:23 pm
acerche wrote:Does anyone know what the "open drill" is that codesnooker refers to in his/her post?
Open drill is nothing but to go through either question or at least last 50 questions of OG 11 from each sections 2-4 days prior to real GMAT. You need not to solve the question completely but to figure out only how to start each question. The more quick your start is, the least time you will spend in exams on thinking to start the question.

Hope this helps...

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by rebounder2 » Mon Oct 20, 2008 7:43 pm
Normally if I just spend a decent amount of time on each question I can avoid mistakes. My problem is that I tend to breeze through the test, and then afterwards find that I've made a couple of mistakes because of going through them so fast.

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by codesnooker » Mon Oct 20, 2008 9:40 pm
rebounder2 wrote:Normally if I just spend a decent amount of time on each question I can avoid mistakes. My problem is that I tend to breeze through the test, and then afterwards find that I've made a couple of mistakes because of going through them so fast.
How could it be?
After deriving the answer did you recheck the question that what exactly author has asked and did you find the exact thing? If yes, then I guess it is problem with fundamentals and if no then do so as I stated. I am sure you will never got anything wrong, even if you are half slept in the test. If you have read my previous post then you will come to know that I had already tested in real GMAT and believe me I was half slept at that time because of poor sleeping habits.