Practice Test for Critical Reasoning- 2 - GMAT MCQ

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.

The counselor suggests that frequent arguments are a cause of marital disharmony. One way to weaken that conclusion is to show that the disharmony came before the arguments (i.e. the disharmony caused the arguments). This is suggested in A which is the best answer.

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.

First look for the statements that help explain why there continues to be a large number of corner shops. Choice A suggests that they stock different things; B suggests that they are more conveniently located; C suggests their main business does not compete with supermarkets'; D suggests that they find favor with the community who would be likely to patronize them. The least relevant (and therefore what we are looking for) is the fact that they make home deliveries because it is not clear whether the supermarkets do the same.

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.

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).

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).

When creating GMAT critical reasoning questions, test writers know exactly what you will be thinking about when certain scenarios are developed, and they deviously use your own mind against you. You must learn to fight this natural instinct: always question the first thing you think about in a critical reasoning question…it is usually a trap! Just as the positive/negative number properties were used to distract you in the DS sample question covered here, so the “obvious” answer plays the same role here. 

Most people immediately gravitate to (D) in this question (you are looking for a premise that improves the quality of the conclusion): if farmers are able to plant twice as much corn because they have reduced the width between rows, then that would explain how they can make a lot more profit. Answer choice (D) seems perfect and most people pick it: “with the spacing between rows cut by half, the number of plants grown per acre will almost double.” 

However, in critical reasoning you must learn to be extremely particular with the given conclusion. The conclusion in this stimulus is the following: “the new machine will allow corn growers to double their profits per acre.” Yet, you are also given an important fact in the argument that will qualify the statement in (D): “Corn planted this closely will produce lower yields per plant.” If you plant twice as much corn but you know for a fact that the closer rows will mean a lower yield per plant, then it is impossible to double profits from twice as many plants in closer rows. Additionally, the answer in (D) states “almost double,” which makes it even weaker. You want the answer to be (D) because that is what your mind anticipates, but numerous elements make it conclusively incorrect. It is really not telling you anything new and it does not at all explain how the farmers can still double profits even if yields are lower per plant. 

The correct answer (A) is not expected nor particularly satisfying, but it is the only one that works. If the need for costly weed control is lessened by the narrow rows, then the combination of more corn and lower expenses can explain how profits would be doubled by farmers even with lower yields per plant. Remember that profits involve two components: revenue, which in this argument cannot explain the doubling of profits by itself, and costs, which if reduced along with increased revenue from more corn can explain a doubling of profit even with reduced yields. With practice, you will learn to be very suspicious about your first reaction when reading GMAT critical reasoning questions. 

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.