Summarize Argument
The stimulus itself doesn’t provide an argument, but the question stem asks us why current automobile-emission enforcement may not be effective in controlling pollution. In other words, we need to weaken the conclusion that current enforcement is effective. The method of enforcement (i.e. the support for that conclusion) is that pollutant levels in exhaust are measured while a car is idling.
Notable Assumptions
The conclusion we’re weakening assumes that cars emit similar or higher levels of pollutants while they’re idling than while they’re in motion. In other words, it assumes that a test while a car is idling will not find a significantly lower pollutant level than the car emits while being driven.
A
As an emission-control technology approaches its limits, any additional gains in effectiveness become progressively more expensive.
This does not undermine the effectiveness of current enforcement, because the expense of continuing to improve emission-control technology has nothing to do with how reliable emission-control testing is. This is just irrelevant to the conclusion we’re weakening.
B
The testing devices used must be recalibrated frequently to measure pollutant levels with acceptable accuracy.
This does not undermine the effectiveness of current enforcement, because we can’t assume that the testing devices are not frequently recalibrated. It’s equally possible that they are frequently recalibrated, in which case current enforcement seems fine.
C
The adjustments needed to make a car idle cleanly make it likely that the car will emit high levels of pollutants when moving at highway speeds.
This undermines the effectiveness of current enforcement by rebutting the assumption that emissions are similar when idling and when in motion. If passing the test by idling cleanly then leads to higher highway pollution, that’s not an effective enforcement method.
D
Most car owners ask their mechanics to make sure that their cars are in compliance with emission standards.
This does not undermine the effectiveness of current enforcement. All this tells us is that most people want to pass the control test, not whether or not the test actually works. This is irrelevant to whether or not current enforcement is effective.
E
When emission standards are set, no allowances are made for older cars.
This does not undermine the effectiveness of current enforcement. Just knowing that older cars don’t get a free pass doesn’t help us figure out whether current emissions testing is doing its job. This is irrelevant.
This is an Argument Part question, so we have to describe the role played in the argument by the statement that "many major cities had similar ratios of police officers to citizens, yet diverged widely in their crime rates."
Like all other LR questions, we try to identify the conclusion and the premises first.
This passage is sneaky. It start by telling us that "many people believe X". Normally, when we encounter a passage that starts like that, what's the upshot? What's the conclusion?
That those people are wrong in their moronic beliefs.
I mean, if I just told you "Look man, I know that lots of people believe X, but Y". You actually get a lot of information out of this right?
You must hear me communicating to you that those people are wrong. The structuring of that sentence, using "but" says that much.
In this passage, we're suppose to hear that increasing the number of police officers is not the only way to remedy crime. That's the unspoken conclusion.
Why should we believe it?
Just look at all these major cities with about the same number of cops to citizens (say, 1 cop for every 1,000 citizens). Yet, they all have very different levels of crime.
We are prodded to draw the conclusion that there must be some other factor that influence the level of crime. In other words, number of cops isn't the only factor. That's answer choice (E).
(C) is wrong because it's not clear what counts as a "proof". If they mean validity, then certainly this argument doesn't meet that high standard. Additionally, (C) says there are other factors that are "more important" than the number of cops. We have some information that there exists other factors, maybe. But we have no information about the relative causal strength of those factors. Which one is more important?
(D) is wrong because the idea of "having no effect" is very different from the idea of "being one causal component amongst many".
Summarize Argument: Counter-Position
The author seems to disagree with people who think that increasing police numbers is the only way to reduce crime. There’s no outright statement of disagreement, but the rest of the argument proceeds as though disputing those people’s view. Specifically, the author cites statistical evidence: various cities with similar police-to-population ratios have very different crime rates. This leads to the implied conclusion that boosting police numbers isn’t the only way to lower crime rates.
Identify Argument Part
The statistics cited in the argument are support (i.e. a premise) for the implicit conclusion that it is not the case that increasing police numbers is the only way to solve crime.
A
establish that the number of police officers does not need to be increased
Like (B), the author never takes a stance on whether or not police numbers need to be increased. The argument doesn’t do this, and nor does any part of it.
B
illustrate the need for increasing the number of police officers in major cities
Like (A), the author never offers a suggestion on whether police numbers should or shouldn’t be increased, in major cities or anywhere else. This isn’t in the argument at all.
C
prove that there are factors other than the number of police officers that are more important in reducing the crime rate
The author doesn’t say anything about whether other factors are more important than the number of police in reducing crime. The argument is just meant to suggest that other factors make a difference, not say which is most important.
D
demonstrate that there is no relation between the number of police officers and the crime rate
The author never denies that police numbers make a difference to crime rates, just that they’re the single, only factor. The statistics suggest that something else might also contribute to lowering crime rates, not that police numbers are irrelevant.
E
suggest that the number of police officers is not the only influence on the crime rate
This correctly identifies that the statistics act as a premise to support the conclusion that factors other than police numbers could help to address crime.
Summarize Argument
The essayist says we must make sure that any major change to scientific procedure is worth it—that the benefits outweigh the costs. The essayist then presents support for the idea that we should proceed carefully in the form of specific examples of possible changes to science. At the end, the essayist emphasizes that the changes would come at a high cost, thus underscoring the point that we need to be sure changes are warranted.
Identify Conclusion
The conclusion is the essayist’s call for caution: “we need to determine whether the changes are warranted, taking into account their price.”
A
We should not make changes that will alter the character of science.
The essayist never says we shouldn’t make changes, just that we need to be certain the benefit of any changes makes the cost worth it.
B
If we regulate science more closely, we will change the character of science.
The essayist only mentions changes to regulation; it's unclear if this means closer or just different regulation. Either way, the claim that the character of science will change lends support to the call for caution. If anything, (B) is a premise, not the conclusion.
C
The regulation of science and the conducting of science can be changed.
This is just context that allows us to understand the essayist’s argument. The point of the argument isn’t whether or not science can be changed, but that we should think carefully about making those changes.
D
The imposition of restrictions on the conduct of science would be very costly.
This is a premise. The essayist’s claim that restrictions would be costly supports the idea that we should consider the costs when thinking about whether to impose such restrictions.
E
We need to be aware of the impact of change in science before changes are made.
This captures the essayist’s conclusion. The rest of the argument is designed to support the idea that we should first fully understand if changes would be warranted by understanding their impact, including their benefits and costs.
Summarize Argument
The manager concludes that the nuclear plant is safer than most other plants where the plant’s employees could work. As evidence, he cites the fact that the nuclear plant’s rate of injuries is less than half the national average for industrial plants.
Notable Assumptions
The manager assumes that a claim about safety can be derived solely from a statistic about injury rate. This means that he doesn’t believe the magnitude of each individual injury should be factored into any discussion of safety. The manager also assumes that injuries on the job are identified immediately, rather than later in life once employment has finished. It could be that the type of work required at nuclear plants exposes workers to harmful chemicals with latent effects, or that the work is physically demanding.
A
Workers at nuclear power plants are required to receive extra training in safety precautions on their own time and at their own expense.
Whether or not we know if other industrial plants have similar protocols in place, it’s hard to see how this could weaken the manager’s argument. If anything, it makes it possible nuclear power plants really are less dangerous than other plants.
B
Workers at nuclear power plants are required to report to the manager any cases of accidental exposure to radiation.
Like (A), we don’t know if this is true of other industrial plants, too. And like (A), this gives another reason why the manager may well be right about nuclear power plant safety.
C
The exposure of the workers to radiation at nuclear power plants was within levels the government considers safe.
This suggests that nuclear power plant workers aren’t experiencing an additional health risk that other industrial plant workers wouldn’t be exposed to. If anything, this helps the manager’s position.
D
Workers at nuclear power plants have filed only a few lawsuits against the management concerning unsafe working conditions.
It seems nuclear power plant workers don’t find working conditions particularly unsafe. This seems to support the manager’s claim that nuclear plants are relatively safe.
E
Medical problems arising from work at a nuclear power plant are unusual in that they are not likely to appear until after an employee has left employment at the plant.
While nuclear power plants have fewer injuries to report each year, the workers suffer nuclear-plant-unique medical problems once they leave their job at the plant. These problems may outweigh the statistic the manager cites.