PanpaliaAnshul wrote:
GMATNinja - Can you pls explain this argument in detail as I didn't get this thoroughly ?
Thanks,
Anshul P
This question is asking which hypotheses is best supported by the information in the passage. Let's take the answer choices on by one:
Quote:
(A) Most people who suffer from allergies or other such immune disorders are left-handed rather than right-handed.
We know that "left-handed persons suffer more frequently than do right-handed persons from certain immune disorders." So if you picked a random group of say 100 left-handed people and another random group of 100 right-handed people, you'd expect more of the left-handed people to have immune disorders. But this doesn't mean that
most people who suffer from immune disorders are left-handed, as answer choice (A) says.
That's because we don't know the balance of left-handed versus right handed people
in general. If the majority of people are right handed, for example, there could still be more right-handed people with immune disorders, even if right-handed people suffer from immune disorders less frequently. Since the hypothesis that
most people who suffer from immune disorders are left-handed is not supported by the passage, (A) is out.
Quote:
(B) Most left-handed mathematicians suffer from some kind of allergy.
Just because left-handed people suffer from immune disorders such as allergies more frequently than do right-handed people, this doesn't mean that
most left-handed people have some kind of allergy. If only 1% of right-handed people have an allergy, for example, then the percentage of left-handed people with allergies could be as low as 2% (or 1.000001%) - so definitely not
most left-handed people. (B) is out.
Quote:
(C) There are proportionally more left-handers among people whose ability to reason mathematically is above average than there are among people with poor mathematical reasoning ability.
The passage tells us that left-handers tend to have an advantage over the right-handers on "tasks controlled by the right hemisphere of the brain." Additionally, we learn that "mathematical reasoning is strongly under the influence of the right hemisphere in most people."
So if
mathematical reasoning is largely controlled by the
right hemisphere, and if left-handers have an advantage over right-handers on tasks controlled by the right hemisphere in most people, we'd expect that left-handers would
generally have an advantage over right-handers when it comes to
mathematical reasoning.
Following this logic, if we took a random sample of left-handers and a random sample of right-handers, we'd expect the mathematical ability of the left-handers to be higher in general. And if that were true, more of the left-handers would have above average mathematical abilities than the right-handers. Let's hold on to (C).
Quote:
(D) If a left-handed person suffers from an allergy, that person will probably be good at mathematics.
The passage makes no connection between left-handed people who suffer from
allergies and left-handed people who are
good at mathematics. And although we'd expect left-handers to have an advantage over right-handers in terms of mathematical ability, that doesn't tell us whether
any particular left-hander is "
good at math." Since it's not supported, (D) is out.
Quote:
(E) There are proportionally more people who suffer from immune disorders such as allergies than there are people who are left-handed or people whose mathematical reasoning ability is unusually good.
The passage doesn't tell us anything about the proportion of people
in general who suffer from immune disorders. Nor does it tell us much about what proportion of left-handed people are good at mathematical reasoning -- aside from the fact that the proportion is bigger than it is for right-handers. As a result, we have
no basis to compare these two groups of people, and (E) is out.
So we're left with (B).
I hope that helps!
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