Hello,
SwagatamGhosh. I am guessing you wanted an Expert reply to the question, so I will provide one. As I typically do, I take a look at the question before the passage so that I know how to frame what I read.
Quote:
Which of the following, if true, would cast the most serious doubt on the conclusion drawn by the argument?
This is a straightforward
weaken question, and we need to weaken the argument or conclusion. We do that by sticking to exactly what the conclusion says.
Quote:
For every 100 car accidents on the road, not more than 30 are caused by female drivers. Hence it can be concluded that women are less prone to cause car accidents on the road than men are.
The opening line is a premise that will lead to the argument. Out of
every 100 car accidents, no more than 30
are caused by female drivers.
The second line is the conclusion. Apparently,
women are less prone to cause car accidents, compared to men.
In order to weaken this conclusion, we want to find an answer that allows us to reconsider whether women may not be less prone to cause car accidents based on the statistics cited. We cannot attack the statistics themselves, only the conclusion drawn from them.
Quote:
A) Female drivers on average own more expensive cars than male drivers do.
The type of car driven by anyone is an irrelevant concern when the issue is to assess whether, once again,
women are less prone to cause car accidents. That is, knowing the relative cost of the type of vehicle driven by women or by men does not provide any insight into the matter.
Quote:
B) Male drivers are much more likely to have been using a mobile phone while causing the accident than are female drivers.
Now we are getting into why accidents may have occurred, but such a cause still does not touch on the frequency with which males or females actually cause car accidents in general. This information, then, has no bearing on the conclusion we need to weaken.
Quote:
C) Male drivers take better care of their cars than do female drivers.
This sort of roundabout answer can get some test-takers into trouble, since the logic might go that a car that is in better shape is more likely to outperform another car, and who are the drivers taking
better care of their cars? But the answer proves unsatisfactory in that we have to fill in a could-be-true scenario and make it a must-be-true condition. Just because someone takes better care of a car does not make that
driver any less susceptible to causing a car accident.
Quote:
D) Out of all car drivers on the road, ninety percent are male.
This makes sense. If nine out of ten car drivers are males, then there should statistically be more car accidents caused by male drivers. All things being equal, we might expect ninety percent of car accidents to be caused by male drivers. The statistics from the first line of the passage only tell us that female drivers cause no more than thirty percent of such accidents. Although this is not firm proof that women are
more prone to causing car accidents than men—for all we know, women could be causing only one percent of all car wrecks, such is the nature of
not more than—we do at least have a reason to doubt the conclusion that women, based on the statistics cited, are necessarily
less prone to cause car accidents. All we need to do is check (E) for another possible contender.
Quote:
E) Heavy vehicles such as trucks and buses are almost always driven by male drivers.
Another vehicle-type answer, no more pertinent than (A). All we care about, since the conclusion is what we need to weaken, is who is causing car accidents on the road, men or women, and in what proportion they are doing so. This information gives us nothing new to consider to that end.
Of the options listed, then, (D) is the best answer. Needless to say, the question and its battle-of-the-sexes focus would NOT appear on the GMAT™, but if you find yourself fishing around for questions on the forum, I see no harm in taking on such a side challenge. For GMAT™ purposes, though, stick to official questions from GMAC™.
Good luck with your studies.
- Andrew
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