I concur with you that E is the answer

The key words are " open land" which, if correctecly understood, is land without many dwellers.
E: population of country Y is more scattering than that of country X --> it's more difficult to find "open land" in Y than in X --> the proposal to build wind farm in Y weakened.

But, then why there's a premise about the population density of the countries? ..

B seems a contender but since we don't have information about the area of the two countries' territories, we can't conclude anything

This is C.

X's population is denser. Thus, Wind farms should be built in Y.

A: Irrelevant
B: This is tempting but doesn't really explain why the mill's should not be built in Y. This requires us to make additional assumptions about greater population.
D: Doesn't weaken, both have the same land mass.

E. Says that population is very dense in one spot for X, but Y is spread out.
Just think of any state with a mega-major city: Illinois . Has Chicago and... thats about it. Chicago contains the majority of the population of Illinois. Now lets compare to say Ohio. Ohio has several major cities, but nothing compared to Chicago. And Ohio's pop is about equal but spread out. Assuming both have same land mass, its easy to see why Ohio would be a worse place to put wind mills.


Now judging from your comments, I can see that E is probably not the answer.

So I say C. The argument assumes that electricity will be purchased outside of Y. I thought this might be something that COULD weaken the argument, but this doesn't really follow the premises as E does. E perfectly explains why its not a good idea to put the mills in Y.

However, we must remember that when weakening the argument, we have to look for two types of choices: one that produces a piece of weakening evidence or one that exposes a faulty assumption.

The argument assumes that both countries will share electricity. This is why choice C is correct.


However, come test day Id still say E. Both are plausible. I guess E just requires us to assume that sparse population means worse for windmilss. This is a very iffy CR if you ask me.


Whoops made an error, fixed it in my reasoning for E with the above example of Ohio and Illinois.

A,C and D out of scope.
B - only population without the land area will not give any conclusion.
E is the answer.

Thanks, quite a stimulating discussion. OA is E.
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Wind farms, which generate electricity using arrays of thousands of wind-powered turbines, require vast expanses of open land. County X and County Y have similar terrain, but the population density of County X is significantly higher than that of County Y. Therefore, a wind farm proposed for one of the two counties should be built in County Y rather than in County X.

Type - weaken
Boil it down - a wind farm proposed for one of the two counties should be built in County Y rather than in County X.
- How big is each country -If the country Y is very small , then it might not have sufficient vast expanses of open land .
- How is the population distributed ?

A. County X and County Y are adjacent to each other, and both are located in the windiest area of the state.- Irrelevant
B. The total population of County Y is substantially greater than that of County X. - Irrelevant
C. Some of the electricity generated by wind farms in County Y would be purchased by users outside the county. - Irrelevant
D. Wind farms require more land per unit of electricity generated than does any other type of electrical-generation facility.- Irrelevant
E. Nearly all of County X’s population is concentrated in a small part of the county, while County Y’s population is spread evenly throughout the country. - Correct - if this is true , then there will be expanses of open land available in county X
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Premises:
Wind farms need vast expanses of open land.
Population density (people/sq mile) of X is higher than Y. (This means X may have 1000 people and 10 sq mile area giving a density of 100 while Y may have 2000 people but 40 sq mile area giving a density of 50)
A wind farm has to be made in one of the two counties.

Conclusion:
Make it in Y

We need to weaken the argument.

A. County X and County Y are adjacent to each other, and both are located in the windiest area of the state.

No argument against Y and in favour of X.

B. The total population of County Y is substantially greater than that of County X.

In the example we have taken above, the population of Y is substantially greater than that of X

C. Some of the electricity generated by wind farms in County Y would be purchased by users outside the county.

Irrelevant. Doesn't give an argument against Y in favour of X. Same may happen if installed in county X. How electricity will be used is immaterial. We are focusing on where it is more feasible to set up the farm.

D. Wind farms require more land per unit of electricity generated than does any other type of electrical-generation facility.

We are not looking for arguments against wind based electricity generation.

E. Nearly all of County X’s population is concentrated in a small part of the county, while County Y’s population is spread evenly throughout the country.

We need vast stretches of land for a wind farm. X will probably have those since its population is concentrated so there will be sparsely populated areas too. In County Y, population is evenly distributed on land so we may not have vast areas of sparse population. It then makes better sense to set up the farm in X. This is correct.

Answer (E)
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Karishma
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GMATNinja, VeritasPrepKarishma, adkikani
Guys just need a thought validation:

Based on answer choice B & Question stem we can conclude this:
X has less population(eg:1000) and higher density (concentrated in areas)
Y: has more population(eg:2000) and lower density. (Not as concentrated as people in X are)

Now cant we say based on the above facts that X has a better probability of providing more expanses of open land than Y because X has lesser population and higher density? Or could we reject B by saying that we don't know about the geographic placement of population chunks that E clearly states?

I see that E has a clear hit in piercing through the conclusion, But I am trying to find a better rejection explanation for B. I will appreciate any input.

Thanks
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2. He who asks a question is a fool for five minutes; he who does not ask a question remains a fool forever.
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Thanks VeritasPrepKarishma. Appreciate your input.
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1. Well Begun is Half done
2. He who asks a question is a fool for five minutes; he who does not ask a question remains a fool forever.
3. The night is darkest just before the dawn