Since anyone who supports the new tax plan has no chance of being elected, and anyone who truly understands economics...

Naz September 10, 2013

"Anyone who supports the new tax plan had no chance of being elected."

SNTP ==> not CE
CE ==> not SNTP

"Anyone who truly understands economics would not support the tax plan."

TUE ==> not SNTP
SNTP ==> not TUE

THEREFORE:

"Only someone who truly understands economics would have any chance of being elected."

CE ==> TUE
not TUE ==> not CE

The flaw here comes from attempting to combine our two principles:

CE ==> not SNTP and TUE ==> not SNTP

Just because the sufficient variables CE and TUE have the same necessary variables, does not mean you can combine them. By combining these principles, the author is assuming not SNTP ==> TUE because CE leads to not SNTP but not SNTP is necessary in our second principle.

Remember, just because something is a vegetable, it does not necessarily mean it is a carrot. Similarly, in this case, just because someone does not support the tax plan doesn't necessarily mean they truly understand economics. If the variable "not SNTP" were the sufficient condition of the second sentence, then we could use the transitive property to conclude "CE ==> TUE." While this is not the case, it is clearly what the author is attempting to do.

(A) is incorrect because the stimulus does not ignore this possibility. The second sentence clearly states all people who truly understands economics do not support the new tax plan. Therefore (A), some people who truly understand economics do not support the new tax plan would be included in that.

(B) is incorrect because it is irrelevant. The flaw here is assuming not SNTP is sufficient for TUE. (B) does not address this flaw.

(C) is incorrect because of the same reason as (B). Again, the flaw here is assuming not SNTP is sufficient for TUE. (C) does not address this flaw.

(D) is CORRECT because by assuming not SNTP ==> TUE, the author is overlooking the possibility that some people who do not support tax plan don't necessarily truly understand economics. "Not SNTP" is necessary for TUE, so it is possible that someone who is "not STNP" is also "not TUE." Therefore, the argument is flawed because the author is ignoring this possibility.

(E) is incorrect because just like (B) and (C) it does not address the authors assumption that "not SNTP" is sufficient for TUE.

Hope that helps! Let me know if you have any other questions

joryjes August 29, 2018

I'm having an issue with the questions like this that we can diagram. I don't see how the S and N diagramming translates to answer the question. In other words, the sentences that I'm able to diagram don't necessarily help me answer the questions because I simply don't understand how to apply them properly. Please help.

Max-Youngquist August 30, 2018

@joryjes if the diagrams aren't helping you answer the question, perhaps leaving the sentences intact is a better strategy for you for this question. For this question, we are looking for a flaw in the argument. Since on the LSAT we always have to accept the premises given to us, we know there is some flaw with the conclusion "only someone who truly understands economics would have any chance of being elected."

The question stem's wording of "ignores the possibility" is a useful clue that can help us knock out certain answer choices. "Ignores the possibility" suggests that the use of the word "only" makes the conclusion too restrictive. Therefore there must be additional groups of people (other than just those who truly understand economics) that DO have a chance of being elected. So we are looking for other groups of people that have a chance of being elected. We are NOT looking for groups of people who have NO chance of being elected. So we can knock out (B),(C), and (E) because they all reference groups of people who "have no chance of being elected."

That leaves (A) and (D). (A) simply restates the premise "anyone who truly understands economics would not support the tax plan," so (A) clearly has not found a NEW group of individuals that was not considered before. That leaves (D) as the only remaining answer. I hope thinking through this question in a new way is helpful for you!

Maybeillgetlucky May 2, 2019

what about C? isnt that also an assumption because they're assuming that just because somebody does not support the tax plan means that they do not have a chance at being elected?

Ravi May 2, 2019

@Maybeillgetlucky,

Great question. The first part of the stimulus tells us that anyone
who supports the new tax plan has no chance of being elected. This
still leaves open the possibility that someone who does not support
the tax plan also may have no chance of being elected. Thus, (C) isn't
the correct answer since the argument is not ignoring this
possibility.

Does this make sense? Let us know if you have any other questions!

Samantha-Alexis June 8, 2019

Can you please do a video going over how you got the answer for this question? I am also having a hard time understanding the diagrams and how to chose between B and D.

Ravi June 9, 2019

@Samantha-Alexis,

The team is working diligently on adding as many video explanations as
possible. Feel free to direct any support related issues to our
support staff by tapping "support" from the left menu or by calling
855.483.7862 ext. 2 Monday-Friday 9am-6pm PT. I'll also let them know
that you'd like a video for this one.

Let us know if you have any questions!

bb042745 June 30, 2020

To Ravi's point about C, is it the word "chance" that is the key? The contrapositive is CE --> not STNP, so if there is a chance of being elected, there is also the "chance" (prob) of not being elected. Thank you for answering.

shunhe July 3, 2020

Hi @bb042745,

Thanks for the question! So the issue here isn’t that (C) uses the word “chance,” the issue is that it doesn’t address the correct problem. Let’s look at the stimulus again to figure out what exactly the flaw is. I’ve diagrammed it as follows:

Support —> ~Chance of being elected
Understands —> ~Supports
Conclusion: Chance of being elected —> Understands

So it seems that the argument is taking the contrapositive of the first statement to get Chance —> ~Support. But then they try to illegally chain that to the second premise; they have the second premise backwards and they think it’s supposed to be ~Understands—>Support. So the correct answer choice should reflect that; it should reflect that not everyone who doesn’t support the tax plan is necessarily going to understand economics. And that’s exactly what (D) says, which is why (D) is the correct answer choice here. (C) is about the wrong parts, it’s about not supporting the tax plan and not being elected, but the issue here is with the second premise about not supporting the tax plan and not understanding economics.

Hope this helps! Feel free to ask any other questions that you might have.