January 26th, 2010 | 
Author: The function of government is to satisfy the genuine wants of the masses, and government cannot satisfy those wants unless it is informed about what those wants are. Freedom of speech ensures that such information will reach the ears of government officials. Therefore, freedom of speech is indispensable for a healthy state.
Which one of the following, if true, would NOT undermine the conclusion of the argument?
- People most often do not know what they genuinely want.
- Freedom of speech tends ultimately to undermine social order, and social order is a prerequisite for satisfying the wants of the masses.
- The proper function of government is not to satisfy wants, but to provide equality of opportunity.
- Freedom of speech is not sufficient for satisfying the wants of the masses: social order is necessary as well.
- Rulers already know what the people want.
Highlight to see answer: D
Please post your explanations in the comments below!
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Most discussions of the factors contributing to improvements in public health greatly underestimate the influence of the values held by individuals. This influence is indicated by the fact that the astonishing decline in mortality from infectious disease during the past century was primarily due to an improvement in living conditions. To a substantial degree, these improvements depended on the emphasis by an increasing share of the population on cleanliness, prudence, and moderation.
The main point of the passage is made primarily by
(A) analyzing existing data on medical practices and health outcomes
(B) presenting a set of related cause-and-effect assertions
(C) applying several general principles to a specific case
(D) presenting a general observation and supporting it with several specific examples
(E) refuting in detail a commonly accepted argument
Highlight to see answer: B
Please post your explanations in the comments below!
GMAT critical reasoning questions often ask you to identify the assumption of an argument. The first step in doing that successfully is understanding what, exactly, they mean by “assumption.” An assumption in GMAT-speak is the unstated link somewhere in the chain of evidence and conclusion. Finding the assumption means, basically, finding that gap in the argument and filling it.
Assumptions can be roughly divided into “necessary” and “sufficient,” and your approach to tackling an assumption question depends in part on which kind of assumption you’re dealing with. A necessary assumption MUST be true in order for the conclusion to follow logically based on the evidence presented. Take, for example, the following simplified version of a GMAT question:
Jennie wears glasses. Jennie also gets A’s in chemistry. Therefore, Jennie must be smart.
Which of the following assumptions is necessary to support the conclusion above?
Here, you’re looking at finding the unstated idea that MUST BE TRUE in order for the argument to work logically. Take a look at the possibilities:
a) Jennie gets good grades in all of her science classes.
b) All girls named Jennie are smart.
c) Jennie wouldn’t wear glasses if she wasn’t smart.
d) Some people who get A’s in chemistry are smart.
e) Everyone who gets an A in chemistry is smart.
Now, a few of these choices support the argument’s conclusion. But only one of them is actually necessary to the argument. Let’s looks at them one at a time.
a) Jennie gets good grades in all of her science classes.
This isn’t an assumption of this argument at all. Jennie’s other science classes are outside the scope of the argument, since they are addressed in neither the evidence nor the conclusion.
b) All girls named Jennie are smart.
This choice would certainly support the conclusion; if this were true, then the conclusion would HAVE to be true. But is this statement NECESSARY to the conclusion? No. Other girls named Jennie don’t have any necessary significance to this argument. So this is not a good choice.
c) Jennie wouldn’t wear glasses if she wasn’t smart.
Again, this choice would be SUFFICIENT to make the argument’s conclusion follow from the evidence. But is it necessary? No. So we’ll bypass this one.
d) Some people who get A’s in chemistry are smart.
This is the correct choice, because it MUST be true in order for the evidence to follow logically from the conclusion. What if this wasn’t true, and no one who got an A in chemistry was smart? If that were the case, then the conclusion would not be true, based on the evidence that Jennie gets A’s in chemistry.
e) Everyone who gets an A in chemistry is smart.
Once more, this choice is sufficient to support the conclusion, but it’s not necessary. So it’s not the correct answer to the question that is being posed.
Now, hopefully you noticed that the correct answer here is the least extreme relevant statement. That doesn’t always have to be the case, but for questions that ask for necessary assumptions, it’s a good general guideline. Be wary of answer choices that are extreme; they will often be sufficient, but not necessary, and will therefore trick test-takers who aren’t careful in evaluating what exactly the question has asked them to find.
But what if the question paired with that argument looked more like this?
Which of the following assumptions, if true, best supports the conclusion above?
Well, in that case, the answer choices would look more like these:
a) Jennie gets good grades in all of her science classes.
b) All girls named Jennie are smart.
c) Jennie gets A’s in her physics class.
d) Some people who get A’s in chemistry are smart.
e) Some people who don’t wear glasses are smart.
Just as in the last example, choice a) is not relevant to the argument as an assumption. But here, choice b) is the correct answer, because if that statement is true, then the conclusion is absolutely true. Choices c) and e) are irrelevant in the same way that choice a) is, since physics and people who don’t wear glasses aren’t at issue here. Now, choice d) is NECESSARY to the argument, but it is not the BEST support to the conclusion. Even if it IS true that some people who get A’s in chemistry are smart, that doesn’t guarantee that Jennie is.
Moral of the story: keep a close eye on what the question is asking for, and read accordingly.
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Some good cooks are gourmet cooks who pride themselves on always using extravagantly rich ingredients in elaborate recipes. Some good cooks can be characterized as fast-food cooks. They may use rich ingredients as long as the recipes are easy to follow and take little time. Other good cooks are health food enthusiasts, who are concerned primarily with the nutritional value of food. But even though not all good cooks are big eaters, they all enjoy preparing and serving food.
If the information in the passage is true, which one of the following CANNOT be true?
- Most good cooks do not use extravagantly rich ingredients.
- Everyone who enjoys preparing and serving food is a good cook.
- More good cooks who use extravagantly rich ingredients are big eaters than are good cooks who do not use such ingredients.
- There are fewer good cooks who enjoy serving and preparing food than there are good cooks who are big eaters.
- Gourmet cooks, fast-food cooks, and cooks who are health food enthusiasts are all big eaters.
Highlight to see answer: D
Please post your explanations in the comments below!
As we’ve seen, flaw questions on the GMAT follow predictable patterns: the flaw always in some way addresses either how the evidence is being interpreted to lead to the conclusion, or how the evidence was obtained. Let’s take a look at a few specific examples of common GMAT flaws.
Real Numbers v. Percentages
At Company X, 15% of the male executives took advantage of the corporate “Family Leave” program last year, enjoying 6 weeks of paid sabbatical after a birth or adoption in their family. Only 10% of female executives at Company X took advantage of the program. Therefore, it appears that more male executives than female executives at Company X are interested in programs that promote leave options for personal reasons.
There are actually two major flaws here, and we’ll look at the one that ISN’T the title of this sub-section first, just to get it out of the way: the evidence isn’t sufficient to support the conclusion. The conclusion is about the “interest” of executives in “programs that promote leave options for personal reasons,” but the evidence only discusses percentages of executives who were involved in one specific program. Drawing a conclusion about programs in general based on that evidence is unsound. Also, participation alone is not necessarily indicative of the interest in the programs; maybe people ARE interested, but just haven’t had new babies in their families.
The more standard flaw here, though, is the “real numbers versus percentages” issue. Evidence is presented about percentages, and based on that evidence, a conclusion is drawn about quantity. But the conclusion is flawed: what if there are 100 male executives at Company X, and 200 female executives? In that case, there would be 15 male executives taking Family Leave, and 20 female executives; since 20 is clearly more than 15, the conclusion would not be properly drawn in that case. We can see, then, that percentage evidence alone is not sufficient to support a conclusion regarding “real number” quantities.
Causation v. Correlation
Studies focusing on North Americans show that single men have an average lifespan of 72.1 years; married men have an average lifespan of 73.4 years. However, married women live an average of 75.4 years, 2.1 years less than single women, who have an average lifespan of 77.5 years. Researchers have concluded, based on the data from those studies, that husbands suck the life-force out of their wives, prolonging their own lives at the cost of their spouses’ longevity.
Okay, first of all, the premise behind that scenario is absolutely a joke; just trying to bring a little levity to the GMAT preparations here! But seriously, the issue here is that there is a correlation between two occurrences (the increased lifespans of married men and the decreased lifespans of married women) and the argument inappropriately assumes that there must be a causal link between those occurrences. Whenever you see an argument that presents two events—let’s call them X and Y– that occur together, and that then concludes that one event, X, must be causing the other event, Y, you should look for the possibility that Y in fact causes X, or that some outside factor, Z, is causing both X and Y.
Necessary v. Sufficient
In order to successfully navigate the Great Lakes Trail, a 47-mile hiking trail fraught with unsteady terrain, one must have a pair of supportive hiking boots. Drew recently purchased a pair of the most comfortable and supportive hiking boots on the market. Therefore, Drew should have no trouble navigating the Great Lakes Trail when he goes on his hiking trip next month.
Now, I know we’ve seen a lot of necessary/sufficient issues in past discussions, but in flaw questions, the application is simpler. The correctly-identified flaw here would be that the argument takes a condition that is necessary for achieving the goal of completing the hike, and has treated it as though it is sufficient. Good boots are necessary; without them, Drew couldn’t make the hike. But are they ENOUGH? What if Drew has a horrible virus and can’t even get out of bed, let alone go for a 47-mile hike? The boots are not, by themselves, SUFFICIENT to ensure success on the hike. As a reader, be on the lookout for arguments that don’t differentiate between necessary and sufficient conditions.
