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CR-An unknown simian virus

Expert replies
by minnie666 » Tue Sep 20, 2016 12:54 am
An unknown simian virus recently killed off nearly half the human population of a remote jungle town. Because the disease spread at an alarming rate—victims usually exhibited signs within 8 hours of exposure, and many died within 36 hours—the simian virus, if an outbreak occurs again, is likely to cause more deaths than has any other previous virus.



Which of the following pieces of information most effectively calls into question the validity of the conclusion?

(A) The Zairean strain of the Ebola virus, known as Zaire ebolavirus, has a mortality rate of nearly 75%.

(B)The village in which the outbreak of the unknown simian virus occurred is located in a country that has had several viral outbreaks in the last two decades.

(C)Viruses that have very little time to incubate before destroying their hosts tend not to lead to widespread epidemics, because quarantines are put in place before the disease can spread.

(D)The town in which the outbreak occurred had only fifty people, of whom twenty-four died.

(E)Viruses tend to be most destructive in densely populated areas, oftentimes spreading amongst thousands of people before any quarantine can be put in place.


I am confused about (A).Because Ebola virus has a higher mortality than the simian virus, if Ebola outbreaks in this town, then 75% of the population will die! More than 50% caused by the simian virus.So I think A also weakens this argument.
I don't think (A) is wrong just because the 75% of mortality doesn't claims more deaths than the unknown simian virus.
Help please!
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Source: — Critical Reasoning |

by ceilidh.erickson » Sat Sep 24, 2016 6:12 pm
I actually agree with your reasoning (in large part). I don't think this is a particularly well-written question. (By the way, ALWAYS LIST YOUR SOURCE!! That way other students can get information on which sources are high-quality).

The conclusion of this argument is: if an outbreak occurs again, is likely to cause more deaths than has any other previous virus.

We're given information about the mortality rate (nearly half) and the time frame (36 hours) of the outbreak in this particular town. It would be reasonable to conclude that a larger outbreak would be devastating. The logical leap, however, is that we can compare the NUMBER of people who would die from this disease to the number who have died from ANY OTHER DISEASE, ever.

If we want to WEAKEN this argument, we need to cast doubt on the either the fact that it will affect large numbers of people, or the comparison to other diseases.

A) I'm with you - I do think that this weakens the comparison of this disease to any other disease. The issue, though, is that it doesn't address NUMBER. Perhaps only a small number of people have contracted this disease, in which case 75% would not be MORE people than will die of this simian virus.

B) irrelevant to our ability to compare. Were those outbreaks worse than this one?

C) This definitely weakens the idea that a large number of people will be affected (though it doesn't address the comparison issue. Not that a right answer has to perfectly address everything).

D) Number of people who died initially is irrelevant to the number who might die if the disease spread elsewhere.

E) This says nothing about whether this particular disease will be particularly destructive.
Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
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by ceilidh.erickson » Fri Oct 21, 2016 4:29 pm
Hi Minnie - following up. Could you please post your source?
Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
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by minnie666 » Fri Oct 21, 2016 5:29 pm
ceilidh.erickson wrote:Hi Minnie - following up. Could you please post your source?
Sorry,I don't know how to do it! I found this when practicing on Magoosh.
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by ceilidh.erickson » Fri Oct 21, 2016 6:13 pm
That's all I meant - what company you got the question from.

Thanks!
Ceilidh Erickson
EdM in Mind, Brain, and Education
Harvard Graduate School of Education
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