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Old LSAT Questions

alessandraalessandra Free Trial Member
edited June 2013 in Logical Reasoning 20 karma
Hi! Is anyone else looking at 10 Actual, Official LSAT Preptests, even though they are less relevant? Let's talk about them here!

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  • alessandraalessandra Free Trial Member
    20 karma
    Preptest 7, Section 4, Question #:12

    This question asks us to choose which statement is undermined by the stimulus. To summarize, it says that corporate clients are using an ad. campaign that gives politicians free air time. The correct answer choice says that an ad. campaign is useful only if is persuades the audience.

    I do not see how the language in the stimulus contradicts the answer choice in any way. The stimulus does not say that the advertising campaign ONLY provides free publicity and air time. How do we know that a company can't use it to persuade the audience?

    This might be a loosely written question, but I want to make sure my reasoning isn't wrong.
  • alessandraalessandra Free Trial Member
    20 karma
    Preptest 9, Section 2, Question #23

    This is straightforward logic, but I am finding it really difficult. The question consists of two or statements:

    You are a or b, and you are x or y. If you are b, you are x. So all a are y.

    How is this diagrammed? The question asks what must be assumed to come to the conclusion.

    The answer is x-->b.
  • alessandraalessandra Free Trial Member
    20 karma
    Preptest 9, Section 2, Question #25

    This is a necessary assumption question, I think. The question stem is: "The argument assumes that." Using the negation method, answer choice B (as opposed to A, which is correct) really seems like the best choice.

    The stimulus talks about how medical research is usually made public only after undergoing peer review and being published in a medical journal. It concludes that even though it takes time, it's necessary because the public might otherwise make decisions based on bad research.

    The correct answer reiterates that peer research is necessary but can occur without publication in a journal. The one I like says that people apart from the review panel won't be able to adequately evaluate the argument.
  • alessandraalessandra Free Trial Member
    20 karma
    Preptest 10 Section 1 Question # 24

    The diagram of the correct answer choice makes it seem to mean something completely different than it's actually supposed to mean. It contains an "if" that creates a causal relationship that they clearly do not intend. Do they still pull tricks like that?
  • PeterPeter Free Trial Member
    edited June 2013 90 karma
    Addressing PrepTest 7, S4 Q12:

    The stimulus suggests that drawing prime-time coverage and comments from officials are useful consequences of a controversial advertising campaign. Indeed, it doesn't state those are the only consequences.

    However, that still contradicts the answer choice that states usefulness of a campaign is "based _solely_ on" its persuasive powers. The stimulus suggested two other modes in which the campaign is useful while the answer choice states there is only one. That would be a direct contradiction. Without the word "solely" the answer choice would be wrong.
  • PeterPeter Free Trial Member
    edited June 2013 90 karma
    Addressing PrepTest 9, Section 2, Question #23:

    I'm going to make an assumption here that might be faulty but I think based on the stimulus, should be safe to make. a and b are disjoint and x and y are disjoint. That is a <-> not b and x <-> not y. If you're poor, you can't be rich, if you're honest, you can't be dishonest and vice versa.

    we know if you're poor then you're honest
    p -> h

    We want to conclude if you're rich then you're dishonest
    not p -> not h

    We can only arrive at this if
    p <-> h (if and only if)

    In other words, if we must assume the opposite: h -> p
  • alessandraalessandra Free Trial Member
    20 karma
    Thanks!
  • Connor MacLeodConnor MacLeod Free Trial Member
    26 karma
    This is for PT 9 section 2 #25

    A is better over B since negating A would completely wreck the argument since the whole thing is about the necessity to have a medical journal publish finding, however if peer review would happen anyways, without having to be published then there would be no reason to force findings to be published in such a way.

    Answer choice B if negated would just read that some people who do not serve on a medical review panel have the necessary knowledge to evaluate research findings. Just because some do does not mean that error cannot still occur; therefore, the argument is still fine on these grounds
  • pinkpantherpinkpanther Core Member
    3 karma

    OK, working on PT 9 - Section 2 - Question 23:

    This one was tough! I know there are many ways to do this one, so here's my attempt at explaining what's going on:

    The premises can be translated as:

    "Either you're rich or poor"
    /R <---> P

    "You are either honest or dishonest"
    /H <---> D

    "All poor farmers are honest"
    P ---> H

    The conclusion can be translated as:

    "All rich farmers are dishonest"
    R ---> D

    The setup should look like this:

    /R <---> P
    /H <---> D
    P ---> H


    R ---> D

    The first thing to do is to secure the the sufficient clause of the conclusion:

    R

    The only thing that R can link up with is /P, so next link up /P.

    R ---> /P

    There really isn't anything else that we can do with /P, which is our hint that this is where the missing premise starts. The only other approach is working backwards from the necessary clause.

    If we know that the necessary clause of the conclusion is D, let's add that, with some space between, to what we already have.

    R ---> /P ---> ? ---> D

    The only thing that can link up with D in our premise set is:

    /H <---> D

    so let's fill in the blank with /H.

    R ---> /P ---> /H ---> D

    From here, we have reached the conclusion and we used a new connection that wasn't in our premise set, /P ---> /H.

    Unfortunately, this exact statement isn't in the answer set. But we can take the contrapositive of it, which is in the solution set: H ---> P.

    Some of the difficulties of this one are: 1) Choosing which letters to represent the statements. I was tempted to use /R to represent "Poor" and /H to represent dishonest, which highlights the mutual exclusivity. However, it became too confusing for me, so I ended up sticking with the terms used in the stimulus. The second difficulty was 2) realizing that the missing sufficient assumption was smack-dab in the middle of the expanded conclusion and realizing that I had to work "backwards" from the necessary condition.

    This problem was deceptively difficult for me for those two reasons. Hopefully this is a help for someone out there.

    pp

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