Sign up to star your favorites LSAT 139 - Section 4 - Question 21
September 10, 2013
Summary
If the book is both as important and as well written as Skiff says, he’ll get a promotion. Why? Because as long as the book is published this year, Nguyen will certainly urge the dean to promote Skiff, in which case the dean will surely do so.
We can simplify the conditional conclusion by kicking up the sufficient condition and taking for granted that yes, the book is as important and as well written as claimed.
We can simplify the conditional conclusion by kicking up the sufficient condition and taking for granted that yes, the book is as important and as well written as claimed.
Missing Connection
The conclusion is that a promotion is certain given that the book is as important and well-written as claimed, but the premises are all about how a promotion is certain if the book is published this year.
The premises would lead to the conclusion if we knew that as long as the book is as important and/or as well written as claimed, it will be published this year.
A
Skiff’s book will be published this year if it is as important as he claims it is.
The book being as important as claimed becomes a sufficient condition, all on its own, for promotion. So we can now validly conclude that, yes, if the book is as important as claimed (and it also happens to be as well written as claimed), Skiff gets the promotion.
B
Skiff needs to publish a book before he can be promoted.
This says that publishing is necessary for promotion. But we still know nothing about whether the book’s being as important and as well written as claimed will in any way lead to a promotion. So the conclusion doesn’t follow.
C
Professor Nguyen believes that Skiff’s book is well written.
What Nguyen believes is irrelevant. All that matters about Nguyen is whether he urges the dean to promote Skiff. We know Nguyen will do so as long as the book is published this year. Any other facts about Nguyen have no effect on the argument.
D
Skiff’s book will not be published unless it is as important and as well written as he claims it is.
This says that to be published this year—or ever—the book must be as important and as well written as claimed. But there’s still no indication that being that important and well written will be sufficient to get it published. So the conclusion doesn’t follow.
E
Skiff will not be promoted unless Professor Nguyen urges the dean to do so.
This means that Nguyen’s recommendation is necessary (as well as sufficient) for Skiff’s promotion. But we still know nothing about whether the book’s being as important and as well written as claimed will in any way lead to a promotion. So the conclusion doesn’t follow.
This question is difficult because of the obscuring of the premises and conclusion. Here's the premises and conclusion distilled, utilizing the skills we learned in our grammar lessons.
published --> prof. N promise to urge dean to promote S --> prof. N urge dean to promote S --> S promoted
_____________
import & well written --> S promoted
Reducing it, the argument goes:
published --> S promoted
_____________
import & well written --> S promoted
Formulaically, we want to supply the missing premise: import & well written --> published
But, the LSAC did something new this time. They gave us: import --> published
That actually works!
To see why, let's think about an analogous argument.
If you buy milk, then you will use cash. Therefore, if you go to store & gas station, you will use cash.
Formulaically, we want to supply the missing premise: if you go to store & gas station, you will buy milk. But, doesn't that feel a little redundant? What if I just said "if you go to store, you will buy milk."
That also allows us to validly draw the conclusion that "if you go to store & gas station, you will use cash."
In fact, it'll even allow us to validly draw the conclusion that "if you go to store & gas station & mars & russia, you will use cash."
Very clever, those LSAT writers
Sign up to star your favorites LSAT 139 - Section 4 - Question 22
September 10, 2013
Summarize Argument
The author concludes that the magazine will not be the top martial arts magazine in a decade because the publisher has refused to allow the editor to make the changes she’s proposed. These changes are necessary for the magazine to continue to rise as quickly as it has, and it would become the top magazine were it to continue rising at that rate.
Identify and Describe Flaw
This argument mistakes a sufficient condition for a necessary condition. If the magazine were to continue rising as it has for the last ten years, then it would certainly become the top magazine. However, we’re given no reason to believe that this is the only way in which it could. Given that the argument fails to establish this condition as necessary, the author cannot conclude that the magazine will not become the top magazine just because it can’t maintain the same quick rate of ascent.
A
identifies some changes required for the magazine’s circulation to continue its rapid increase and concludes from this that no other changes are needed
This is descriptively inaccurate. The argument concludes that the magazine will not rise to the top, not that there don’t need to be any other changes.
B
equates a reduction in the rate at which the magazine’s circulation is increasing with a decline in the magazine’s circulation
The author never claims that the magazine’s circulation will decline. The effect of refusing the editor’s changes would simply mean it wouldn’t rise as quickly. The flaw is assuming that the magazine must rise as quickly as it has in the past in order to reach the top.
C
draws a conclusion that simply restates a claim that is presented in support of that conclusion
The argument’s conclusion is that the magazine will not reach the top spot in ten years. This claim was nowhere in the premises.
D
takes a single fact that is incompatible with a general claim as enough to show that claim to be false
We’re not given any facts that aren’t compatible with the magazine failing to reach the top spot. The argument’s flaw is assuming that maintaining its rate of ascent is necessary to reaching the top spot.
E
treats an occurrence that will ensure a certain outcome as something that is required for that outcome
This describes how the argument assumes that the magazine must rise at the same rate it has in the past in order to reach the top spot. We’re told that maintaining that rate was sufficient for it to reach the top, but the author assumes that it’s necessary.
Sign up to star your favorites LSAT 139 - Section 4 - Question 23
September 10, 2013
Summarize Argument
The author concludes that the trait of resistance to pesticides would be passed from domesticated crop plants to their weed relatives. This is based on an experiment in which domesticated radishes were able to pass on the trait of flower color to their weed relatives. In addition, the trait of pesticide resistance is often a genetically engineered trait.
Notable Assumptions
The author assumes that pesticide resistance would have the same ability to be transferred to relatives as does the trait of flower color. This overlooks the possibility that something about pesticide resistance — for example, the fact that it’s often genetically engineered into the plant — might prevent it from being passable to weeds. The author also assumes that observations concerning radishes are applicants to other crop plants.
A
It is much easier in principle for genetic traits to be passed from wild plants to their domesticated relatives than it is for such traits to be passed from the domesticated plant to the wild relative.
This compares ability to transfer traits from wild to domesticated with ability to transfer from domesticated to wild. But the argument doesn’t concern transferring from wild to domesticated.
B
When the ratio of domesticated radishes to wild radishes in the field increased, the speed with which the flower color passed to the wild radishes also increased.
This suggests we can speed up the rate of transferring flower color by including a greater proportion of domesticated plants. But this doesn’t relate to whether a different trait — pesticide resistance — can be transferred.
C
Radishes are not representative of crop plants in general with respect to the ease with which various traits are passed among members of closely related species.
This undermines the argument by suggesting the radishes used in the experiment might not support a conclusion about trait transfer in other kinds of plants.
D
The flower color of the domesticated radishes had not been introduced into them via genetic engineering.
If anything, this undermines the argument by pointing out a difference between the trait of flower color and the trait of pesticide resistance. This suggests the transferrability of flower color might not apply to pesticide resistance.
E
It is more difficult for flower color to be transferred between domesticated and wild radishes than it is for almost any other trait to be passed between any two similarly related plant species.
If the transfer of flower color observed in the experiment is more difficult than almost any other kind of transfer of trait between any related plant species, that suggests transfer of pesticide resistance is likely to be easier, which supports the claim that it will occur.
Sign up to star your favorites LSAT 139 - Section 4 - Question 24
September 10, 2013
Summarize Argument: Causal Explanation
Parents who always praise their children for every effort, whether successful or not, can actually hurt their children’s self-esteem. If parents praise their kids for both what they achieve and what they just try, the kids will start to ignore all praise. In the end, it’s like they don’t hear any praise at all.
Identify Conclusion
Parents who constantly praise their children for every effort, whether it succeeds or not, actually harm their children’s self-esteem.
A
Parents should praise their children for their achievements.
The stimulus doesn’t make this argument. It talks about the harmful effects of overpraising kids but doesn’t express an opinion on whether parents should praise their kids for achievements. Moreover, if anything, the passage suggests that parents should praise less.
B
Children whose actions are praised undeservedly eventually learn to discount all words of praise.
This is a premise. The stimulus explains that when kids get too much praise, they start to ignore it. This claim supports the main conclusion that overpraising kids can actually hurt their self-esteem. Since this claim supports the argument, it isn’t the main conclusion.
C
Parents need to distinguish between their own expectations for their children and what their children are actually capable of accomplishing.
The stimulus doesn’t make this claim. It doesn’t tell parents what they should or shouldn’t do. It simply states that a certain behavior can lead to an unwanted outcome. If anything, the passage merely suggests that parents should praise their children less.
D
Children’s self-esteem will suffer if their parents uniformly praise their attempts to accomplish things regardless of their success or failure.
This accurately captures the stimulus’s main conclusion. The stimulus argues that parents who consistently laud or “uniformly praise” their children’s attempts to accomplish something will eventually harm (or “erode”) their children’s self-esteem, causing it to “suffer.”
E
Children will develop low self-esteem if their parents do not praise them when they succeed.
The stimulus does not make this claim. It argues that too much praise harms children's self-esteem, not that too little praise causes low self-esteem. Also, the passage says too much praise lowers self-esteem but does not necessarily mean it leads to "low" self-esteem.
Sign up to star your favorites LSAT 139 - Section 4 - Question 25
September 10, 2013Roger: The dams are already producing electricity at optimal capacity. So regardless of whether they are breached, we will have to find additional energy sources for the region.
Speaker 1 Summary
Pauline concludes that if the dams are breached, electrical costs will skyrocket. This is because the region has a growing population and a booming industry. (The phrase “given the region’s growing population and booming industry” is a premise.)
Speaker 2 Summary
Roger concludes that whether or not the dams are breached, we will have to find additional sources of energy for the region. This is because the dams are already producing electricity at the optimal capacity.
Objective
We’re looking for a point of agreement. The speakers agree that there will likely be growing demand for electricity in the region.
A
production from other energy sources cannot be increased in the near future to compensate for electricity production lost by breaching the dams
Roger doesn’t express an opinion. He says we will need to find additional sources. But he doesn’t say anything suggesting an opinion about whether we can or cannot find an alternative energy source in the near future.
B
there will be no significant decrease in demand for electricity in the region in the near future
This is a point of agreement. Pauline believes electrical costs will skyrocket if the dams are breached. Roger believes we’ll have to find additional energy sources. This suggests they don’t think electricity demand will decrease significantly in the near future.
C
if the dams remain in service but do not operate at optimal capacity, electrical costs in the region will rise
Not a point of agreement. Pauline doesn’t comment on what will happen if dams are not at optimal service. If dams are breached, electric costs will rise. But if dams are not breached, but still in service, we don’t know Pauline’s opinion.
D
some environmentalists who advocate saving the salmon believe that that goal overrides concerns about electrical costs
Roger doesn’t express an opinion. He doesn’t comment on environmentalists and their view concerning saving the salmon.
E
finding additional energy sources will not decrease the electrical costs in the region
Pauline doesn’t express an opinion. She doesn’t discuss finding additional energy sources and what that will do to electrical costs. She acknowledges electrical costs will skyrocket if the dam is breached. But that doesn’t indicate an opinion on other energy sources.