All questions of Strategies and Practice for Critical Reasoning for GMAT Exam

The Dean concludes that the number of postgraduates studying physics is likely to decline. To weaken that conclusion we need to show that there need not be a decline. The best answer is C because it shows that physics students mainly choose careers in applied areas rather than a career in pure science, and it is the pure science that is affected by the cuts. The number of undergraduate students is really irrelevant unless we know something about the percentage that continue in the same field (eliminate A). What is happening in Chemistry is not clearly linked to Physics (eliminate B). Even if staff members increase we cannot be sure that postgraduate students will increase as the staff might be teaching undergraduates or the move might be to improve the staff/student ratio (eliminate D).

This moderately difficult CR question presents a great example of one of the oldest tricks in the CR playbook: the “word shift” con. It is extremely common for test writers to develop a detailed and elaborate argument that then involves a subtle shift in wording or scope when moving from the premises to the conclusion. 
When attacking a “weaken” question like this, you should always start by deconstructing the argument and understanding exactly the line of reasoning. To summarize this argument:
Premise One: Krenland’s steelmakers are losing domestic sales because of lower priced imports that often result from unfair practices banned by international treaties.
Premise Two: These imports are going to result in job losses in Krenland’s steel industry
Conclusion: The government should reduce cheap steel imports in order to protect not only the steel industry but also industrial employment in Krenland.
Did you notice that shift in wording and scope in bold? If you do, this problem is relatively easy; if you don’t, you will waste a lot of time and probably get it wrong. Because the whole argument is about the steel industry, many people overlook the change in shift and wording from “employment in the steel industry” to “industrial employment.” They are not the same thing! If you see this shift, then you will recognize that the conclusion has a serious flaw: how do we know that stopping cheap steel imports is good for other industrial companies in Krenland and thus industrial employment in general?
The goal of this question (which you should be crystal clear on before moving to answer choices) is to attack the line of reasoning and expose a flaw in the argument. If you notice the shift in scope, then you can anticipate the answer: what if most industries in Krenland greatly benefit from the cheap steel because their products become more competitive domestically and internationally? In other words, it is entirely possible that stopping cheap steel imports will HURT industrial employment, which the conclusion suggests this action will protect.
Answer choice (C) perfectly exposes this potential scenario and is thus correct. 
When analyzed carefully, you see that none of the other answers do anything to show why stopping cheap imports will NOT protect steelmakers or industrial employment. Most of these incorrect answers seek to explain why the imports are cheap, which is not important but is satisfying for many test-takers who don’t notice the word shift:
(A) does nothing to weaken the argument because the issue at play for steel makers is their domestic sales, not their exports.
(B) the international treaties are not relevant to the conclusion – why the imports are cheap does not matter.
(A) again, it is not important to know how or why the imports are cheap – the conclusion is just to stop them
(B) this can again explain the difference in prices for steel, but does not address the conclusion.

The argument suggests that seat belt use might not increase the chances of survival, and so the best way to oppose the argument would be to find cases where seat-belt use does increase survival. Hence A is the best answer.

There is a 'missing link' between saying that the fruit is sour and saying that removing the sourness will make the fruit acceptable to American tastes. The missing link is an 'assumption' in this case. Obviously the missing statement should be that Americans don't like sour foods. So now we have found one assumption but this is an 'except question' and so we need to find three more! Since we are relying on the fruit for vitamin C it should be obvious that the author thinks the new process will not take away most of the vitamin. The author also thinks a market exists or they would not be starting to grow the fruit. He or she mentions salads as a way to use the fruit but there is nothing to suggest that there are no other ways to use the fruit and so D is not assumed and is the correct answer. He or she also assumes that there is nothing else wrong with the fruit. (Note: most students go wrong on 'except' questions!)

We are looking for something to strengthen the idea that people are unenthusiastic about campaigns related to animals that are not viewed in a positive light. Answer B relates a similar situation in which people were unenthusiastic about a creature until it was seen in a new (presumably positive) way. Giving a similar example is one way to support an argument, and it is the best option available here.

The first part is a statement of the viewpoint of some people and as such could be called a position, a conclusion or something similar. Since it is not an assumption or a finding we can eliminate B and C. The author presents evidence to suggest that this point of view is not correct and so we can eliminate A. The second part is a finding of some research and is not an assumption, hence we can choose D.

Munchon's contention is that buying their products safeguards health. To weaken that argument we can show that, for some reason, their foods might not be healthy. Munchon claims that the products are healthy because they contain only "natural ingredients". But bacteria and molds are 'natural' as are certain poisons derived from plants! Hence the word 'natural' is no guarantee of healthful properties.

Ada tells Jay that there are as many people in her office as in his, but fails to mention how many computers there are. If there is one computer to each person in her office, her argument is be invalid. To strengthen her argument she should show a similar ratio of computers to users. Thus C is the best answer. The actual number of people, computers or breakdowns is not really important as it is the usage that is in dispute. Thus answers A, D and E are not suitable. The type of computers is, no doubt, important in robustness, but the point that Ada is answering is whether there are too many people handling the same computer, and so we cannot choose B.

We cannot know that Jay thinks his computers are the best, and so A can be rejected. Similarly it is not possible to say whether he thinks he does not need more people, or thinks that software is not important, or even that no other office has a similar usage per computer. (Notice that these boldface strong words make us very suspicious.) The fact that Jay calls the frequency of breakdowns high, tells us immediately that he thinks the frequency is above average, and so B is correct.

The argument recommends that migraine sufferers should try to find the one trigger for their headaches and then avoid this trigger. This would still be a good plan even if the trigger did not always cause a headache " it is better to be safe than sorry" and so the best answer is B. The other choices present actual problems. If it is almost impossible to identify triggers then the recommendation is futile (eliminate A). This recommendation would be a problem if the triggers are so common that it is almost impossible to avoid (eliminate E). It is also a problem if the recommendation is for a person to avoid one trigger when, in fact there are many triggers for that same person (eliminate D). Internal hormonal triggers are not something that can be found and avoided (eliminate C).

Since this is an 'except' question we must find four ways for Barbie to strengthen her position. The one answer that doesn't strengthen her conclusion will be correct. Barbie wants to use an agent and choices C and E point out benefits of the agent, while choices A and B point to reasons why the internet is not necessarily better. A careful look at D suggests that the agent might not always get the seller the best price, and so that is the best answer.

The hypothesis that obesity is a factor in the development of the disease cannot really be tested by looking at the current weights of the patients. They might have lost weigh recently (for any reason such as doctor's advice or even illness). Thus before concluding that obesity is NOT a factor in the development we need to know about their weights before the onset of the disease. Answer D is closest to this suggestion. In answer choice A the height is irrelevant as is the parental weight in E. In B, the weight at diagnosis is already too late to infer anything about the development of the disease. And in C what happens after the disease has developed is also irrelevant.

The conclusion states that the tonsils have no function in the body. To weaken this conclusion we should try to show that the tonsils do have a function, at least at some point in human life. Comparison with another organ is not really useful, as other organs might or might not have a demonstrable function, and might be very different from tonsils, and what happens in other animals is also not directly relevant. Thus we can discard A and C. The statement in E is clearly irrelevant in deciding whether tonsils have a function. So that leaves B and D. An organ might develop as part of a system and yet have no function (like the appendix or muscles that wiggle the ear), and so D is not convincing, whereas B suggests that there is a function even though this function can be taken over by another part of the body. Thus B is the answer.

Be careful with 'except' questions. In this case, first find the four statements that would weaken the conclusion; these will be wrong answers Then check that what is left does NOT weaken the conclusion; this will be the right answer. The statements that weaken the conclusion will show that the government should not allocate more funds. Choice A clearly indicates that there is no need for more funds, and so does E. Statements B and C both show that there is doubt about whether the disease is increasing in a way that needs more funds because they suggest the numbers are not a cause for alarm. What a committee suggested four years ago is not really relevant, and so D is the correct answer.