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- Sat Apr 08, 2017 9:51 am
#33978
Complete Question Explanation
Parallel-FL. The correct answer choice is (E).
This is a very useful question, in part because it shows some of the little tricks used by the test makers. Let's start by looking at what happens with the argument.
P. That same sentence contains a separate "some" premise, namely that MR 
CA. Those two statements can be linked together to form the chain MR CA P. On the basis of that relationship, a valid conclusion can be drawn that MR P. "Some" statements are reversible, so this relationship can be read in either direction, and the makers of the test reversed the wording in the conclusion of the stimulus to make it a bit harder to identify as valid.
Moving to the answers, what we want in a correct answer is something with a similar structure (a valid argument with a some and all premise, and a some conclusion, not necessarily in that order), and one that has the same "some/all" connection we see in the premises. Let's look at what we have:
Answer choice (A): This has a totally different structure, with both a none premise and an all conclusion.
Answer choice (B): "not all" can overlap with "some" (and equals "some are not"), so this is less problematic at first glance than it might seem (especially since the term in the stimulus was actually "only a small portion," which is actually equal to "some but not all"). However, there, is no second premise and thus no chain, and therefore the argument has a different structure.
Answer choice (C): Before reading this explanation, stop for a moment and consider what you are looking at here. Just as an academic exercise, how would you diagram this (if you were to do so on the test itself)?
I ask that question because this is one of my favorite contrapositives in LSAT history, showing how conditions can be experienced by any member of the group, whether that's "Tomas," "Mae," or as in this case "some people:"
Answer choice (D): Again, the premise/conclusion structure and terms differ markedly from our stimulus.
Answer choice (E): This is the correct answer choice. Note how they make you wait in this problem, which makes a lot of students nervous in Parallel Reasoning (they want answers fast since they fear the time consumptive aspect of some Parallel questions).
Does this answer have the same structure and terms as the stimulus? Yes. Is it in the same order? No, but that does not matter. Topic and order of presentation are two things that are not relevant in Parallel problems, so we can ignore the fact that conclusions appears first in this problem instead of last as in the stimulus). Here's the structure, reordered to match our stimulus:
Note that, if you simply apply the Elemental Attack to the answers (all-some-some), you are immediately down to (C) and (E). From there our deeper analysis of Formal Logic takes us to (E), but you can see how the LSAT makes sure you know your stuff as far as conditionals, formal logic, and arguments terms and structure.
All in all, a really interesting problem to break down in detail, and you can see so many of the basic elements here at work as far as argument structure, drawing inferences, interesting answer choices, the Parallel Reasoning Elemental Attack and finally what matters in Parallel problems. A great example of how older questions can really teach you the fundamentals of how they make this test!
Parallel-FL. The correct answer choice is (E).
This is a very useful question, in part because it shows some of the little tricks used by the test makers. Let's start by looking at what happens with the argument.
- CA = Contemporary advertising
P = Tries to persuade
MR = Morally reprehensible
P1: CA P
P2: MR CA
(those two premises would be automatically chained together to create: MR CA P)
C: P MR
P. That same sentence contains a separate "some" premise, namely that MR CA. Those two statements can be linked together to form the chain MR CA P. On the basis of that relationship, a valid conclusion can be drawn that MR P. "Some" statements are reversible, so this relationship can be read in either direction, and the makers of the test reversed the wording in the conclusion of the stimulus to make it a bit harder to identify as valid. Moving to the answers, what we want in a correct answer is something with a similar structure (a valid argument with a some and all premise, and a some conclusion, not necessarily in that order), and one that has the same "some/all" connection we see in the premises. Let's look at what we have:
Answer choice (A): This has a totally different structure, with both a none premise and an all conclusion.
Answer choice (B): "not all" can overlap with "some" (and equals "some are not"), so this is less problematic at first glance than it might seem (especially since the term in the stimulus was actually "only a small portion," which is actually equal to "some but not all"). However, there, is no second premise and thus no chain, and therefore the argument has a different structure.
Answer choice (C): Before reading this explanation, stop for a moment and consider what you are looking at here. Just as an academic exercise, how would you diagram this (if you were to do so on the test itself)?
I ask that question because this is one of my favorite contrapositives in LSAT history, showing how conditions can be experienced by any member of the group, whether that's "Tomas," "Mae," or as in this case "some people:"
- P: Good Manager Decision Adequate Data
P: Decision Adequate DataSome
C: Good ManagerSome
Answer choice (D): Again, the premise/conclusion structure and terms differ markedly from our stimulus.
Answer choice (E): This is the correct answer choice. Note how they make you wait in this problem, which makes a lot of students nervous in Parallel Reasoning (they want answers fast since they fear the time consumptive aspect of some Parallel questions).
Does this answer have the same structure and terms as the stimulus? Yes. Is it in the same order? No, but that does not matter. Topic and order of presentation are two things that are not relevant in Parallel problems, so we can ignore the fact that conclusions appears first in this problem instead of last as in the stimulus). Here's the structure, reordered to match our stimulus:
- P1: Son SP
P2: Son TP
(those two premises would be automatically chained together to create: TP Son SP)
C: TP SP
Note that, if you simply apply the Elemental Attack to the answers (all-some-some), you are immediately down to (C) and (E). From there our deeper analysis of Formal Logic takes us to (E), but you can see how the LSAT makes sure you know your stuff as far as conditionals, formal logic, and arguments terms and structure.
All in all, a really interesting problem to break down in detail, and you can see so many of the basic elements here at work as far as argument structure, drawing inferences, interesting answer choices, the Parallel Reasoning Elemental Attack and finally what matters in Parallel problems. A great example of how older questions can really teach you the fundamentals of how they make this test!
Dave Killoran
PowerScore Test Preparation
Follow me on X/Twitter at http://twitter.com/DaveKilloran
My LSAT Articles: http://blog.powerscore.com/lsat/author/dave-killoran
PowerScore Podcast: http://www.powerscore.com/lsat/podcast/
PowerScore Test Preparation
Follow me on X/Twitter at http://twitter.com/DaveKilloran
My LSAT Articles: http://blog.powerscore.com/lsat/author/dave-killoran
PowerScore Podcast: http://www.powerscore.com/lsat/podcast/
