Among people who experience migraine headaches, some experience what

I was doubting between A and D.
Finally I choose D....the wrong one!
Can anybody explain why this one cannot be the right answer?

Hi,

We can use the Kaplan denial test to prove that A must be true (and therefore correct) and that D could be false (and therefore incorrect):

If A were untrue--if susceptibility to classical migraines WAS NOT more dependent on hereditary factors--then there would be no available explanation for the discrepany in likelihood of genetic transmission, and thus that discrepancy could not exist, and thus a part of the passage would become falsified. But in an inference question every part of passage is necessarily true. Thus, choice A must be true.

On the other hand, choice D could be false without falsifying any part of the passage (primarily because the passage did not establish anything that had to be true about "children"--"children" are outside the scope).

TAKEAWAYS:
--we can use the Kaplan denial test in inference questions (many people think it can only be used in necessary assumption questions).
--the correct answer will always be very CLOSE to the passage (notice that every idea of choice A is discussed in the passage either explicitly or implicitly); converesely, facts about "children" cannot be inferred from the text of the passage.

Let x be a number of counts of migraine

General populace: x

Common migraine: Sib=2x; Spouse=2x

Classical migraine: Sib=4x; Spouse=x

From above statistics, we can infer that
brothers & sisters of classical sufferers have 4x chances whereas
brothers & sisters of common sufferers have 2x chances
Because brothers & sisters (siblings) are related by blood, we can
say that hereditary factor play a major role in acquiring classical migraine
than in common migraine.
This is the position of option A.

On the other hand, spouses of common migraine have 2x chances whereas
spouses of classical migraine have x chance
From the statistics, Spouses of common migraine are more prone than are
those of classical migraine.
However, this is not discussed in any of the options.


Do I make any sense or am I over stating what is meant in the stem?

Quite straightforward. It's A. My reasons for choosing this is as follows:

(A) Susceptibility to classical migraines is more dependent on hereditary factors than is susceptibility to common migraines. [Correctly identifies support to the premise and the major part of the passage states the instances for this]
(B) Unmarried adults are more likely to suffer from classical migraines than they are to suffer from common migraines. [There is nothing in the passage that suggests how vulnerable unmarried adults will be]
(C) People who do not experience migraine headaches are unlikely to have spouses who are migraine headache sufferers.[Again, out of scope]
(D) Children of people who suffer from common migraines are more likely than the general population to experience a common migraine.[Out of scope, also]
(E) Between one-quarter and one-half of the general population suffer from either common or classical migraine headaches.[Out of scope]

Among people experience migraine headaches, some experience what doctors call"common" migraines, whereas others experience "classical" migraines. Siblings and spouses of common migraine sufferers are themselves twice as likely as the general population to experience common migraines. Siblings of classical migraine sufferers are four times more likely than the general population to experience classical migraines, whereas spouses of classical migraine suferers are no more likely than the general population to experience such headaches.

Type - Inference
Boil it down - Common migraine - Siblings and spouses have 2x probability of suffering
Classical migraine -Siblings have 4x probability of suffering
Pre-Thinking - the hereditary link is an important factor in classical migraine

The information above provides the most support for which of the following hypotheses?

(A) Susceptibility to classical migraines is more dependent on hereditary factors than is susceptibility to common migraines. Correct answer
(B) Unmarried adults are more likely to suffer from classical migraines than they are to suffer from common migraines. May or may not be true
(C) People who do not experience migraine headaches are unlikely to have spouses who are migraine headache sufferers. Out of scope
(D) Children of people who suffer from common migraines are more likely than the general population to experience a common migraine. May or may not be true as children have not been talked in the argument
(E) Between one-quarter and one-half of the general population suffer from either common or classical migraine headaches. Out of scope

Hi,
I was confused between A and E. I chose E over A because I thought that the argument gave a number of people suffering from migraine.
Please explain.

Thanks in Advance.

Let's review what we're given:

• Siblings of common migraine sufferers are twice as likely as the GP to experience common migraines. (hereditary factor)
• Spouses of common migraine sufferers are also twice as likely as the GP to experience common migraines. (non-hereditary factor)
• Siblings of CLASSICAL migraine sufferers are FOUR TIMES more likely than the GP to experience classical migraines. (STRONGER hereditary factor)
• Spouses of CLASSICAL migraine sufferers are no more likely than the GP to experience classical migraines. (no non-hereditary factor)

If we have a group of people who suffer from common migraines and another group of people who suffer from classical migraines, we can use the information in the passage to discuss how likely it is that their siblings and spouses will also have common or classical migraines.

But the information in the passage does not give us any information to determine the PROPORTION of the GP that actually suffers from one of those types of migraines. Maybe 10% of the GP suffer from common migraines and 15% suffer from classical? Maybe half of the GP suffer from one or the other? Maybe only 1% suffer from each? We have no idea, so (E) must be eliminated.

Looking at the bullets above, it seems that susceptibility to classical migraines is more dependent on hereditary factors than is susceptibility to common migraines.

(A) is the best choice.

GMATNinja, ThatDudeKnows, DmitryFarber, GMATNinjaTwo, IanStewart, MartyTargetTestPrep, RonPurewal, KarishmaB, MarkSullivan, AjiteshArun, EMPOWERgmatRichC, mikemcgarry, sayantanc2k, TommyWallach, Testluv, Bunuel

is the 1st sentence in the passage grammatically correct? does it need 'who'? this is an official question

The first sentence of the passage does require "who." It appears that the person who posted this question mistakenly left out that word.

Bunuel, other moderators: could u pls edit the question accordingly? thanks

Fixed the issue. Thank you for reporting. That's really very helpful!

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