The number of new cases of tuberculosis diagnosed in Country X increased dramatically this year. The country's news media have speculated that the sharp increase in new cases is the result of the tuberculosis outbreak that occurred in neighboring Country Y last year. Health officials in Country X have therefore proposed that all visitors from Country Y must submit to a medical examination before entering Country X.

Which of the following, if true, most strongly suggests that the proposed medical examinations will not help curb the spread of tuberculosis in Country X?
Country Z, which also neighbors Country Y, has not experienced an increase in cases of tuberculosis.
Current medical technology is not capable of detecting all carriers of tuberculosis.
Country X does not have the resources to examine all visitors from Country Y.
Tuberculosis is not spread through human contact.
Citizens of Country Y will not travel to Country X if the proposal is implemented.

.
.
.
.
MGMAt answer (D) This suggests that the visitors from Country Y are not the source of the disease. Thus, testing them would likely do little to curb the spread of the disease.


My answer.....
Choice B...deny this one..so there are some cases of TB that will be undetected. If TB spreads (as per the stimulus it does), then these few cases would be enough to eventually spread in country X. Hence B is correct.

For choice E...
The stimulus doesn't say that human 'contact' is needed to transfer the disease. It may happen that if some one with TB coughs, somebody can get it. TB can be contagious without contact. There is a difference between a 'contagious' disease and a 'contact' disease. Hence I think that E is incorrect.

Dear staff..do you agree about the distinction between 'contact' and 'contagious'?

My two cents.

Agree that B appears to be a borderline choice. Why? Because all we need to do is "help curb the spread". If you can detect (and stop) even one carrier at the airport then you have helped. Not much but more than nothing. But the question asks for which one "most strongly suggests" not just suggests.

D is far more correct. Contact should be broadly defined - note that physical contact is not mentioned. Contact does not mean touching (eg, we have lost contact, these tribes have had no contact with the outside world). All these sentences talk about contact but with no suggestion that one needs to touch.

This is key as one can spread a disease without carrying it in a medical sense. For example, when there was a BSE outbreak in the British Isles everybody needed to disinfect footwear. Every farmhouse, henhouse and pub had disinfection mats in front of them. This is a good example of something that is spread by human contact which would not be picked up on a medical examination.

If you think about medical tests can only test for a subset of the things spread by human contact. Once you are told the entire set is excluded (eg, it is not human contact) you don't care about the precision of the tests - they don't matter.

This argument only explicitly discusses the proximity of X and Y, the TB situation in each country, and the travel of citizens from Y to X. We are not told exactly how the disease spreads, nor would we be expected to use outside knowledge on the matter.

Also, note the exact wording of the question:
“most strongly suggests”--More than one choice can legitimately “suggest” the medical exams will not serve their purpose, but we must select the stronger choice.

“will NOT help” --Don’t overlook the NOT.

“curb the spread of TB”--Curbing the spread of disease is to slow it down, not to stop the spread or prevent the disease entirely.

(B) Suggests that some carriers will still enter X from Y. This certainly weakens the plan, suggesting that it will not be entirely effective, but it fails to show that the exams “will not help” at all.

(D) States that tuberculosis infection is caused by something other than human contact--note that it doesn’t matter what! The medical exam simply restricts entrance to a country (i.e. it prevents human contact by people who fail the exam), so the exam would have no effect on the spread of tuberculosis. To use the language of the question, this choice tells us that the exams “will not help.” This exceeds the threshold of “strong suggestion” called for by the question.

Aragorn, I agree that “contact” and “contagious” are different. For choice (E), wouldn’t the fact that no one from Y would travel to X prevent the spread of TB by either means? Your sneeze argument would at least require people to be in the same country. (E) would thus suggest that the exams might help curb the spread of TB by restricting travel. The distinction between “contact” and “contagious” would only matter if the question were looking for a strong suggestion that “the exams DO help curb the spread.”

The take-aways: Pay close attention to the wording of the question, and don’t overthink the answers!

_________________
Emily Sledge
Instructor
ManhattanGMAT

The number of new cases of tuberculosis diagnosed in Country X increased dramatically this year. The country's news media have speculated that the sharp increase in new cases is the result of the tuberculosis outbreak that occurred in neighboring Country Y last year. Health officials in Country X have therefore proposed that all visitors from Country Y must submit to a medical examination before entering Country X.

Which of the following, if true, most strongly suggests that the proposed medical examinations will not help curb the spread of tuberculosis in Country X?

A)Country Z, which also neighbors Country Y, has not experienced an increase in cases of tuberculosis.
B)Current medical technology is not capable of detecting all carriers of tuberculosis.
C)Country X does not have the resources to examine all visitors from Country Y.
D)Tuberculosis is not spread through human contact.

I need a little help with choice A. Even though MGMAT explains this as a out of scope. But I could not eliminate this as out of scope. My reasoning is:

Whatever news media speculates it is just a speculation not a proven fact. If country Z has not experienced any increase (assuming people also travel there from Y) does not it weakens the whole point.

This choice might not be the as strong as D. I agree Q asks for most strongly. I've not seen so far in any OG Q where two choices supports or weakens and we have to see which one does the most. Am I missing something here.

hi sonu_gmat -

notice that you wrote the following:


of course, you can't assume this. there is nothing in the passage to justify this assumption.
do not make random assumptions and then build a case based on them!

if you don't see the point here, then note that you could just as well assume that people don't travel there from Y (the direct opposite of your assumption). since no evidence is given either way, both assumptions or equally valid. or, more exactly, both of them are equally invalid. you can't build an argument on either of them.



such problems exist.

see #25 in the og verbal supplement (the green book).
in that problem, (a) and (c) both strengthen the argument, but (c) strengthens it more than does (a).

The two contenders are
B. Current medical technology is not capable of detecting all carriers of tuberculosis.
&
D. Tuberculosis is not spread through human contact.

I think Aragorn digressed a bit in the end as he moved the discussion to choice E.

Quoting Emily's response on B
"(B) Suggests that some carriers will still enter X from Y. This certainly weakens the plan, suggesting that it will not be entirely effective, but it fails to show that the exams “will not help” at all. "

Question Statement:
Which of the following, if true, most strongly suggests that the proposed medical examinations will NOT help curb the spread of tuberculosis in Country X?

I disagree with Emily's reasoning that the argument is asking us to find a choice which shows Medical tests will NOT AT ALL help. The questions asks will NOT help curb. It doesn't say eradicate. Moreover, even if a choice shows that it is possible that spread increases despite medical checkup, then the choice will be the correct answer.

My Reasoning:

D. Choice D is incorrect and moreover Out of Scope. We don't have the information that Human Contact is the ONLY WAY an infected human being can spread TB. He can transmit the disease by coughing, sneezing etc.

Only thing which is in scope is "Medical exams".

B. Choice B is closest correct answer as it says that even though, Medical screening happens, it MAY not help curb the spread.

Ron, Need your help.

Hi,

I understand your frustration but let's look at the answer choices carefully as well as your responses. I think the points you make are great, but you've got to stick the exact language of answer choices and not add in your own perception of certain terms such as contact.



Choice B is easier to understand when you look at it in the extreme. Pay attention to exact wording of the text:

B)Current medical technology is not capable of detecting all carriers of tuberculosis.


This statement does not imply that no carriers of tuberculosis can be detected, just that not all can be detected. In the extreme, it is reasonable to see that at least one carrier could be detected using current medical technology and if just one carrier of TB is detected then it can be seen that the screening will help curb the spread of TB.

D is in scope, so the fact that B is within the scope of the argument is irrelevant.

B is incorrect.



The flaw in your reasoning lies in your definition of the word contact. Your reasoning suggests that the phrase human contact does not include coughing, sneezing, etc. In reality those are indeed indirect forms of contact but answer choice D does not differentiate between direct contact, such as touching, and indirect contact, such as sneezing.

In fact, D indicates only that TB is not spread by one human carrier contacting another. If that is the case then, screening of human carriers will not help curb, or reduce, the spread of TB, because humans are not the vehicle by which TB is spread.

More to the point, in the extreme D could be rephrased as "something other than human beings transmits TB to human beings." If that is the case, then screening for human carriers is completely ineffective at curbing the transmission of TB.

Finally, human contact is not out of scope even though it is not explicitly mentioned in the paragraph. The conclusion is based on the assumption that the spread of TB can be curbed by screening visitors of Country X from Country Y, because there is an implied causal link between an outbreak in Country Y and Country X.

Answer choice D properly attacks an assumption that links the outbreaks in either country to travel between the two countries. Human contact is never explicitly mentioned but necessarily implied. That's what makes this a tough question.

Answer choice D is correct.

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Chris Brusznicki
MGMAT Instructor
Chicago, IL

I think this is a good question.The key to this question lies in understanding what "contact" means. For anyone who thinks "contact" invloves physical touch will end by crossing this out.

Thanks..

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Tim Sanders
Manhattan GMAT Instructor