LSAT to study for the GMAT, part 2: Critical Reasoning

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by David@VeritasPrep » Thu Jan 13, 2011 8:22 am
RyanDark -

This is not an old posting! The ones I am amazed at are those that come back around with no replies since 2007!

If you are speaking of "The Official LSAT SuperPrep" this is a book with three official LSAT exams - they are the February exams which is unique because the February exams are not disclosed while the June, Sept./Oct., and Dec. tests are.

With that said, these three exams are official LSAT exams and do fall under the items mentioned earlier in the posting. So feel free to use The Official LSAT SuperPrep it should give you about 150 critical reasoning questions, of which at least 2/3 should be usable for GMAT study. (Also you have another 12 reading comprehension passages if you choose to study those as well).

As to your second point, let me say congratulations on your 90% accuracy rate. You are wise to not want to mess that up. However, I do not believe that studying LSAT questions at this point in your studies will mess up your reasoning style. Let me give you some thoughts.

1) Test takers continue to report that they are seeing tougher questions on the actual GMAT and a greater variety of those questions. Some report getting lots of the more difficult types like one person who said that more than 1/2 of his critical reasoning were assumption questions, or people who are getting lots of rare types (I had 4 "most useful to know" questions out of only 10 critical reasoning back in March), to people getting questions that they simply did not see in the official guide such as certain types of method of reasoning questions. For this reason I would say that throwing in some LSAT questions which are tougher and have a larger variety might be a good thing for you right now.

2) Except for those LSAT questions that are completely different the techniques you have mastered in the OG and VR transfer well to the main question types - strengthen, weaken, inference, paradox, etc.

3) Trust yourself! You have now done about 150 official GMAT questions and you know what these are like - one main conclusion, that conclusion nearly always at the end of the stimulus, usually relying heavily on one main premise, no need for formal logic - so you will know when you confront an LSAT question that is completely different from this. In the case of a question that is very foreign you can either skip it or say, "I will do this one for fun." Just don't get confused, you know what a GMAT question is like.

4) If you start to really struggle on the LSAT questions, I doubt it but if you do, then you can always discontinue and review a few GMAT questions to get your groove back.

Finally, let me say that I am always surprised at how many of the critical reasoning questions posted on Beat the GMAT are actually LSAT questions. And these usually seem to impress people as being a little tricky but well written and generally not at all unfair. Have you tried the LSAT questions that I have posted? There are five so far.

Good luck! You will do well!
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by RyanDark » Thu Jan 13, 2011 10:40 am
Thanks Dave for the reply. I find your posts on CR pretty helpful .I haven't tried doing much LSAT CRs. Planning to start LSAT CR from today onwards by going through your questions. Went through your 2010 GMAT CRs already.
Also, is Veritas Critical Reasoning 2 more advanced than part 1? Also do they contain just practice questions or both strategies and questions.

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by David@VeritasPrep » Thu Jan 13, 2011 2:15 pm
It depends on what you are looking for in strategy. Critical Reasoning 1 covers all the main categories Strengthen Weaken Inference Paradox and Bold Faced Reasoning as well as Method of Reasoning and Mimic the Reasoning. Critical Reasoning 2 covers what many people consider the most difficult type of question - Assumption - in great depth. It also covers other advanced types like Most Useful to Know, Fill in the Blank, Plan questions, and Flaw questions. So each book has strategy.

I suppose that you could say that Critical Reasoning 2 is more advanced although both books have a range of questions including some questions that are more difficult than anything in the Official Guide. (As I mentioned it is good to be prepared!)

Critical Reasoning 2 has 103 questions with detailed explanations (this is something that the LSAT questions I have discussed lack - explanations of the answers).

Critical Reasoning 1 has 55 questions with detailed explanations and a bit more discussion at the beginning. I am partial to Critical Reasoning 2, but I wrote a few of the questions in Critical Reasoning 2 so I may be biased.

Good Luck!

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by missionGMAT007 » Sun Jan 16, 2011 5:42 am
David@VeritasPrep wrote:
3) The best question numbers to study are generally from 1 to 16 in any given LSAT test. The LSAT is arranged in order of increasing difficulty so that questions 1 - 10 are designed so that at least 75% of test-takers will get them right. Questions 11- 16 are more difficult but still closer to what one would expect on the GMAT. Questions 17 to 25 (or 26) are very challenging and should be treated accordingly.
Hi David,
does that mean that the only questions from 1 to 16 are similar to GMAT type questions? Are the questions from 17 to 25 are similar to GMAT type? or is it that they (17 to 25) are just very challenging but still similar to GMAT type?

thanks!

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by David@VeritasPrep » Sun Jan 16, 2011 7:13 am
As mentioned above, the top level Critical Reasoning questions on the LSAT are much more difficult and varied than on the GMAT. This would be expected since Critical Reasoning is fully 1/2 of the points available on the entire LSAT where CR is only less than 1/6 of the GMAT.

For that reason the hardest LSAT questions can be very difficult.

It is also true that there are about 20 different types of CR questions on the LSAT. Of these different types there are several kinds that are fairly common on the LSAT that are very different from anything on the GMAT. For example, on the LSAT there is a type of strengthening question where you must prove the conclusion is 100% true. There is a type of inference question that requires you to use formal logic to see which conclusion is logically valid. These unusual questions are fine to attempt as long as they do not force you to change your technique.

What is true of questions from 17 on in each LSAT Critical Reasoning test section is that they are more likely to be both very difficult and not like those on the GMAT.

If you think of doing the LSAT questions as a way to expand and sharpen your abilities rather than as a way to predict your score on the GMAT then you will learn from these and not get frustrated.

So, I will certainly not guarantee that question 1 - 16 are like those on the GMAT. There will be questions on every test in the first 16 that are not exactly like anything on the GMAT. However, those questions from 1-16 that are unusual might also be doable so that they would be fun to try. The questions from 17 - 25 or 26 are nearly all difficult so that when you get the unusual ones they might be quite confusing.

What I would say throughout the LSAT use it more as a positive training tool rather than getting frustrated if you miss some. Try this:
  • 1. Do your best to understand and approach each question using GMAT categories and techniques.

    2. If a question does not seem to fall within your GMAT experience attempt it by trying to do whatever the question stem asks or just skip the question (depending upon how you have chosen to study).

    3. If you miss a question understand why by first trying to understand it in a GMAT way. If you cannot understand it according to anything in your GMAT experience see if you can make sense of the correct answer.

    4. If you cannot make sense of the question do not worry about it since you will not actually be taking the LSAT!
Good Luck!
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by sohrabkalra » Wed Nov 16, 2011 6:46 am
Hi Dave,

Dug this post out via search on using Lsat questions for CR.

I have two questions
1) How much time on average is okay to give a LSAT CR from gmats perspective. My average turned out to be around 2 minutes per question , so thats about 50 minutes for 25, do you think thats appropriate?

2) I did a quick analysis of the accuracy and heres what came out
Q1-10 - 90%
Q11-16 - 82% (got most of them wrong in a single section of a test)
Q17-25 - 92%

And about 60-70% of what i got wrong were related to Flaw,Organization,Parallel reasoning type of questions ! In LSAT questions i ran into number of questions in which two options left little to differentiate between them, and found parallel reasoning questions a little different from GMAT

How do you think this performance on LSAT is from GMATS perspective, do i need to focus on some specific areas ?

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by David@VeritasPrep » Sun Nov 20, 2011 3:50 pm
Your performance on LSAT questions is a very good sign. You are doing well on these and that shoudl translate to the GMAT.

First, 2 minutes is very appropriate. You would have less time on the LSAT but you are studying for the GMAT so that is fine.

Second, you are correct that the questions can be a little different with the LSAT being more varied and at times more difficult.

Third, the success rate that you show is very good. This will easily translate to the GMAT. You do not need to study specific LSAT types, as you mentioned some are more represented on the LSAT than the GMAT, but you seem to be handling these well.

Great job! Keep studying!
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by sohrabkalra » Mon Nov 21, 2011 1:35 am
Thanks for the inputs!

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by anuragbytes » Wed May 02, 2012 5:02 am
Hi David,

I am really glad that you have written this wonderful thread on LSAT CR.
Like others, i am also trying to improve GMAT CR accuracy by working on LSAT CR.
I have a doubt regarding a LSAT CR Must be true question.Would be really grateful if you can clear my doubts
This question is from PrepTest3 (December 1991),LR1

People with serious financial problems are so worried about money that they cannot be happy.
Their misery makes everyone close to them-family, friends, colleagues-unhappy as well. Only if their
financial problems are solved can they and those around them be happy.

Which one of the following statements can be properly inferred from the passage?

A) Only serious problems make people unhappy.
B) People who solve their serious financial problems will be happy.
C) People who do not have serious financial problems will be happy.
D) If people are unhappy, they have serious financial problems.
E) If people are happy, they do not have serious financial problems

A= Serious financial problems
B= People unhappy
C= Family, Friends, Colleagues unhappy

A-->B
B-->C

A-->C

transitive cause and effect

OA says [spoiler](E)[/spoiler]

I have 2 doubts regarding this question, will be grateful if you can help

1) I am confused , as all this while i have been studying that any answer choice that reverses the order from Cause-->Effect
to Effect-->Cause or that negates the relationship is wrong(like not cause--> not effect,) , but the OA does that.
Could you please help where i am going wrong?

2) Does GMAT tests on this kind of logic?

regards

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by David@VeritasPrep » Wed May 02, 2012 5:42 am
First, thanks for the reply! I am glad to know when the things I write help someone.

Next, the question that you have posted above is an example of something that is NOT likely to show up in the Critical Reasoning section of the GMAT. This question relies entirely on formal logic. GMAT questions do not rely entirely on formal logic.

Even so let me help resolve your doubts on this one. You said:
I am confused , as all this while i have been studying that any answer choice that reverses the order from Cause-->Effect to Effect-->Cause or that negates the relationship is wrong(like not cause--> not effect,) , but the OA does that
But the relationship here is not cause and effect it is formal logic which means that we would use "if...then" statements. That is what the arrows you use actually mean in logic. For example, "stay up late ---> tired next day" is properly stated as "IF you stay up late THEN you will be tired the next day." This is known as the "positive reasoning structure." What is then allowed for is the Conra-positive reasoning structure that is formed by reversing the terms AND negating them at the same time. So here is the other thing that I know from this statement "IF you are NOT tired the next day, THEN I know you did NOT stay up late." Do you see how I did that? I reversed the terms and negated both.

Here is another example. "Business School ---> submitted application" which reads "IF you go to business school THEN I know that you submitted an application." Okay now what else do we know to be true? We know that you NEED an application. That is why the term after the arrow is called the "necessary" term. It is needed in order to have the first term. And the first term is called the "sufficient" because if you have the first term you can follow the arrow and you get the second term automatically since if follows from the first. That means that if you DID NOT submit an application then I know you DID NOT go to business school. Do you see reversed the order and negated both terms.

Okay so now your LSAT example: Premises "Serious financial problems ---> NOT Happy ---> Those around also NOT Happy." Conclusion is written this way since "only if" means that you have the necessary term. "Happy and Those around also Happy ---> NO financial problems."

So this logic is solid. The premises lead to the conclusion. All the conclusion is is the contrapositive of the premises. Terms reversed and negated. Since this is an inference question all you have to do is look for the answer choice that matches what we have written above. Choice E matches the conclusion "Happy ---> NO Financial Problems." That is what E says and that is our conclusion. This would be considered a straight-forward question on the LSAT for those who have studied formal logic since it basically repeats the conclusion.

If you want to think about this in a more GMAT way, forget about the formal logic and try to eliminate answer choices the way that you should be doing on an inference question. If the answer choice COULD BE FALSE then eliminate it.

A) could be false, the stimulus does not say that this is the only way to be unhappy. Surely there are more ways to be unhappy!
B) could be false, it does not say solve your financial problems and automatically become happy. It says you have to solve them in order for it to be possible to be happy.
C) could be false, see what I said about A and B. There are other reasons to be unhappy!
D) could be false, see what I said and A and B and C. Unhappiness does not have to be the result of financial problems.
E) THIS IS IT! We are discussing financial problems as a block to happiness. E is the only answer that captures this correctly.

So there is a mini-discussion of formal logic and then reasons why you do not need to know it! You would not see this question on test day, yet if you did you could still get it right by using process of elimination.
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by anuragbytes » Wed May 02, 2012 9:50 pm
Thanks David.

What I understood from your explanation is that a conditional statement is equal to the its contrapositive i.e.
If A Then B= If Not B Then Not A.

Correct me if i am wrong in my understanding of below
1) If a conditional statement is JUST reversed in an answer choice then its wrong i.e. If A Then B != If B Then A
2) If a conditional statement is JUST negated in an answer choice then also its wrong i.e. If A Then B != If Not A Then Not B

I am following your suggestion of working on LSAT CR sets only in the range of 1-16.
The above question falls in that range and it is not likely to appear on GMAT since it is formal logic question.

Could you please suggest me on below
1) Is this the only form of formal logic or there are others?
2) How many are there? How do i recognize other forms of Formal logic while working on LSAT CR so that i do not waste time on irrelevant portion?
3) Is this kind of formal logic applicable on other question types like Assumptions, Strengthen, Weaken ..etc? ( specifically in relation to LSAT CR since its not likely to appear on GMAT)

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by jainpiyushjain » Thu Mar 14, 2013 12:48 am
Is there any particular section within the LSAT that we should focus on ?
David@VeritasPrep wrote:Using the LSAT to Study for the GMAT Part 2: Critical Reasoning

If you missed part one of this article it is at: https://www.beatthegmat.com/using-the-ls ... 66548.html

Those who have taken both tests will tell you that mastering the Critical Reasoning on the LSAT is great preparation for the GMAT. What they do not mention is the months of studying this typically requires. If you have unlimited amounts of time, and/or you just really want to be good at all sorts of critical reasoning problems, the way some people are good at Sodoku, then study away! But assuming that your goal is to do well on the GMAT there are some rules you should follow if you choose to use LSAT Critical Reasoning questions.

Rules for using LSAT Critical Reasoning to study for the GMAT:

1) Understand the differences between the two tests and the limitations of using one to study for the other. The Critical Reasoning on the LSAT is far more varied than on the GMAT, is generally harder than on the GMAT, and relies more on formal logic. For this reason, studying certain kinds of LSAT problems can actually confuse you and cause you to focus on things that simply do not appear on the GMAT. (For example, you should probably avoid questions that rely too heavily on formal logic). There are no GMAT questions that absolutely require formal logic. In later posts I will examples of questions that might be confusing to study...

2) Focus on the types of questions that commonly appear on the GMAT - specifically focus on Strengthen, Weaken, Assumption, Inference, Resolve the Paradox Questions, and Questions that ask you what role a stated portion of the stimulus plays. Other types of questions on the LSAT can help you to work on your reasoning abilities in general and if you have lots of time are interesting to try, but are not necessarily applicable to the GMAT. (An example of a question directly applicable to the GMAT is given below).

3) The best question numbers to study are generally from 1 to 16 in any given LSAT test. The LSAT is arranged in order of increasing difficulty so that questions 1 - 10 are designed so that at least 75% of test-takers will get them right. Questions 11- 16 are more difficult but still closer to what one would expect on the GMAT. Questions 17 to 25 (or 26) are very challenging and should be treated accordingly.

4) Try to find "take-aways", or points that you can apply to questions that you will see on test day. This is not only important when you are studying LSAT questions but anytime you are studying. Ask yourself, "What does this question ask me to do that is similar to something that I have seen before?" If you miss the question, find out what you did wrong not so that you could get this question right in the future but so that you can get this type of question right next time. And if you got the question right, figure out what you did right so that you can try to repeat that success.

5) Where to find LSAT questions: LSAT questions are most easily (and legally) available in the "10 Actual, Official LSAT" series from LSAC - the Law School Admissions Council. Each of these books contains 10 LSAT tests which adds up to about 500 critical reasoning questions (of which half or more will be appropriate for GMAT students). Each book also contains 40 reading comprehension passages (reading comprehension will be discussed in the third part of this article). The question below comes from the "10 More Actual, Official LSAT PrepTests" book. This book contains tests from the late 1990s. It does not matter which edition of the "10 Official LSAT" books you buy as you are not looking for the latest LSAT questions, but just some good critical reasoning. If you buy one of the older books you can probably get it cheap. I saw new copies of the older editions for about $5 U.S.

EXAMPLE:

The following is an LSAT question that is similar to those you would see on the GMAT, same type of question, etc.
This question comes from the September 1998 LSAT Test. This is from section 2 question #10. I have taken it from the "10 More Actual, Official LSAT PrepTests" book, page 260.


10. Commercial Passenger Airplanes can be equipped with a collision-avoidance radar system that provides pilots with information about the proximity of other airplanes. Because the system warns pilots to take evasive action when it indicates a possible collision, passengers are safer on airplanes with the system than on comparable airplanes not so equipped, even though the system frequently warns pilots to evade phantom airplanes.

Which one of the following is an assumption on which the argument depends?

A) Passengers feel no safer on airplanes equipped with the radar system than on comparable airplanes not so equipped.

B) Warnings given by collision-avoidance system about phantom radar signals are not caused by distorted radar signals.

C) The frequency of invalid warnings will not cause pilots routinely to disregard the system's warnings.

D) Commercial passenger airplanes are not the only planes that can be equipped with a collision-avoidance system.

E) The greatest safety risk for passengers traveling on commercial passenger airplanes is that of midair collision.

As you can see this is a question that would not seem out of place on the GMAT. It is an assumption question as is clear from the question which states that the "argument depends" on the assumption. Please give your answers to this question, OA and explanation to follow.

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by David@VeritasPrep » Thu Mar 14, 2013 5:39 am
There are two critical reasoning sections. This article is about using LSAT questions to study for the GMAT Critical Reasoning Section.

You can also look to the Reading Comprehension section (there is one RC section per LSAT Test).

The section that does not apply at all is the "Logic Games."

As far as critical reasoning, as this article states, there are questions that apply to the GMAT better than other types.
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by nicktim » Sat May 25, 2013 3:03 pm
David@VeritasPrep wrote: The Critical Reasoning on the LSAT is far more varied than on the GMAT, is generally harder than on the GMAT, and relies more on formal logic. For this reason, studying certain kinds of LSAT problems can actually confuse you and cause you to focus on things that simply do not appear on the GMAT. (For example, you should probably avoid questions that rely too heavily on formal logic).
Hi Dave,

Thank you very much for your advice regarding using logical reasoning (LR) questions as a practice for critical reasoning (CR) questions. My GMAT is 7 weeks away and I have already completed the CR questions for both OG13 and VR2. For the past couple of weeks, I have been doing one set of LR every other day. After completing 5 LR sets, I have been missing about 5-6 questions per set, on average.

Below are a couple of questions that I missed. After reviewing the answers, I still did not understand the reasoning behind the argument, unfortunately. Could you please let me know if these questions are classified as "questions that rely too heavily on formal logic"? Thank you very much! :)

Example #1
Undoubtedly, one's freedom is always worth the risk of losing one's life. Consider a person who is locked in a bare cement room with no hope of escape. This person is not really living and has nothing to lose.

A flaw in the argument's reasoning is that the argument

(A) presumes, without providing justification, that nothing can have greater value than one's own freedom.
(B) fails to consider that it is not always possible to rebel physically against an encroachment on one's freedom.
(C) generalizes inappropriately from a single extreme case to a universal claim.
(D) fails to establish that the freedom of others is worth taking risks for.
(E) overlooks the possibility that some people do not have the courage to take risks for freedom.


Example #2
One can be at home and be in the backyard, that is, not in one's house at all. One can also be in one's house but not at home, if one owns the house but rents it out to others, for example. So one's being at home is not required for one's being in one's own house.

Which one of the following most accurately describes the relationship between the argument's conclusion and its claim that one can be at home without being in one's house?

(A) The claim is required to establish the conclusion.
(B) The claim represents the point the conclusion is intended to refute.
(C) The claim is compatible with the truth or falsity of the conclusion.
(D) The claim points out an ambiguity in the phrase "at home".
(E) The claim inadvertently contradicts the conclusion.

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by David@VeritasPrep » Sat May 25, 2013 5:39 pm
These are not typical GMAT questions!

These are both sort of fun and a little funny as well.

The first one the correct answer is C. The conclusion is that one's freedom is ALWAYS worth risking one's life. And then it gives a crazy little example about Guantanamo Bay prison. Clearly that does not justify "always."

The second one is one that I have seen before. I will not even trouble you by discussing it. This is the purest example of formal logic not on the GMAT!

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