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Complete Question Explanation

Flaw in the Reasoning. The correct answer choice is (E)

The author of this stimulus discusses N5, a non-caloric fat substitute. The conclusion is presented
in the second sentence of the paragraph: “…N5 is of no use to such people.” The author bases this
conclusion on a single premise: N5 users, who continued to feel hungrier than they would have if
they had they been eating real fat, ended up making up all of the calories saved by eating more.

There is a disconnect in this stimulus that we might notice: N5 is a fat substitute. The subjects
made up for the calories they saved by eating more. As is common with regard to logical reasoning
passages, the test makers hope that we will fail to note this subtle but important distinction.

The question stem which follows the stimulus in this case is, not surprisingly, a Flaw in the
Reasoning question, so the correct answer choice will likely point out the difference between
reduction of fat intake and reduction of total caloric intake.

Answer choice (A): The stimulus deals with people who use N5, so the existence of foods that
cannot include N5 has no bearing on the author’s argument, which deals with the usefulness of N5
for those who use it.

Answer choice (B): Since the important inquiry here deals with the usefulness of N5 for those who
use it as a fat substitute, the existence or absence of mild side effects does not come into play (that is,
N5 might still be useful even if its use brings mild side effects).

Answer choice (C): This answer choice provides us with a less straightforward version of the
following: “some who use N5 don’t care about caloric intake.” This choice fails to point out the
important distinction between fat intake and caloric intake, and, further, plays no role in the author’s
argument about the usefulness of N5 as a fat substitute.

Answer choice (D): Even if people who are aware of the fat substitute’s benefits use more foods that
include N5, this fails to point out a vulnerability in the author’s argument that N5 is of no use as a fat
substitute, so this answer choice cannot be correct.

Answer choice (E): This is the correct answer choice, and the one which points to the vital
distinction between fat intake and caloric intake. If this answer choice is true, then the author’s
conclusion fails, because N5 appears to have value as a fat reducer even if users maintain caloric
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I am having difficulty understanding why (C) is incorrect.

Conclusion: Studies indicate that N5 is of no use to such people [people who need to reduce their intake of fat and to consume fewer calories]

Premise: Subjects who ate foods prepared with N5 almost invariably reported feeling hungrier afterwards than after eating foods prepared with real fat and consequently they ate more, quickly making up for the calories initially saved by using N5.

So (E) makes total sense as the correct answer. "The total fat intake of people who eat foods prepared with N5 tends to decrease even if their caloric intake does not. The conclusion states that users get no use from N5 and this answer indicates that they are getting at least one use.

So on to (C): "Not everyone who eats foods prepared with N5 pays attention to caloric intake. " I thought this answer attacked the study. It very well could be that the study is composed of people who do not need to reduce their fat intake and consume fewer calories. Therefore, they will respond to the cravings by eating more. However, someone who is paying attention to fat and caloric intake would have the cravings, but not necessarily eat more.
 Kristina Moen
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Hi there TOgren,

The conclusion is that N5 is of no use to "those people" aka "people who need to reduce their intake of fat and to consume fewer calories." It's not about people who don't need to reduce their calories. You are making a big assumption that the people in answer choice (C) are the people in the study. We're not really told about the people in the study - who they are (college students? older folks?) and how many there are (5? 20?). But the author is concluding that IF the studies are true (premise!), then the conclusion is that N5 is of no use to those who need to reduce fat & calories. But you hit the nail on the head with answer choice (E)... N5 could still be of use if it reduces fat intake, even if the participants make up ALL the calories (and even if they eat MORE!).

It doesn't matter that other folks might eat N5. But studies show N5 doesn't help folks reduce calories. So the author concludes it wont help those who need to reduce calories (and fat - that added part is the flaw!).

Hope this helps.
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It does! Thanks Kristina
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I am just wanting to be clear. Maybe I am approaching this a little differently and I have been thinking about this problem for a few hours now.
C says that some people would not care about their caloric intake. It seems that the possible solution that is being suggested is just simply changing the definition of the original subjects of the study. Originally they were people who needed to "lower their fat AND lower their calories." So, if that was the case, then C is just kind of being thrown out there and changing the entire scenario and kind of pulling the carpet out from under the feet of the conclusion, so to speak.
E would just be better because it addresses what C does and mentions the lowering of fat, which just seems forgotten in the other answers.
"of no use" is also just strong language.
I was just wondering what your thoughts were on my reasoning about why C is incorrect. Thank you. :)
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I feel I should be more specific..

The change in the subjects of the study that I am speaking of is as follows:

"people who need to lower their fat intake and their caloric intake" >>>>>>>>>> "some of the people are not even concerned with caloric intake."

Then it presents this as if that would be like the flaw, like, "haha, I bet you did not consider some of them didn't even care about calories... even though we originally said they needed to lower them to begin with."

If that makes sense. :P
 James Finch
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Hi Mr. Cheese,

The issue in this stimulus is that we have a group of people who need to do two things: reduce their intake of fat and to consume fewer calories. The conclusion states that the N5 fat substitute is of no use to the people in this group, which logically means that N5 cannot lead to reduced fat intake nor to consumption of fewer calories. But it can only show that N5 does not lead to lower overall caloric intake, but says nothing about lower fat intake. So just from reading the stimulus, the flaw should be clear: the conclusion is far too strong for the evidence provided, because it leaves open the possibility that N5 leads to lower fat intake. Answer choice (E) correctly identifies this flaw.

This is a common flaw tested on the LSAT, designed to see how carefully test-takers are reading the stimuli. Always note the scope of the conclusion and make sure that there is enough evidence given by the premises to support it.

Hope this helps!
  • Posts: 32
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Thank you. The power of the statement "it is of no use" is a very strong statement. It seems I just did not understand what that term actually meant. Very helpful. :)

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