Archaeologist : For 2,000 years the ancient Sumerians depended

Thanks Raksat for the reply!

Yes, the author says that Sumerian civilization collapsed because it relied heavily on irrigation. Choice (B) simply says that if Sumerian civilization had NOT relied heavily on irrigation, it probably would have collapsed eventually. Other factors may have eventually caused its collapse, but those factors didn't cause the collapse. Heavy reliance on irrigation caused the collapse. Thus, the author's argument is not weakened.

Why not E?E also weakens the statement.

Answer should be D. Argument , towards its end states that If moderns rely significantly on irrigation , then they will collapse. D states that modern dont rely heavily on irrigation, so they have less chances of collapsing.

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The author's conclusion is that "A similar fate is likely to befall modern civilizations that continue to rely heavily on irrigation for agriculture." This conclusion is only concerned with civilizations that rely heavily on irrigation. If they continue to rely heavily on irrigation, then they will likely collapse. The conclusion is not concerned with the "many modern civilizations" that DON'T rely on irrigation, so choice (D) is not relevant to the author's conclusion.


As for choice (E), even though the soil contained some toxic salts, the Sumerians were still able to sustain their agriculture. In other words, the level of toxic salts was not a problem. However, because of heavy irrigation, the toxic salts built up and became a problem.

It's a bit like saying that a man had a heart attack because he ate too much fatty fast-food that clogged his arteries. His arteries may have contained some fats before he started eating the fast food, but the fats were not a problem until he continued to eat fast-food, causing the fats to build up to dangerous levels.

GMATNinja help needed boss!

How come answer choice C is correct. It says - "Many" - even if it's 90%, the remaining 10% over the years will create built up salts and eventually the civilization will fall, it would make sense if this was "ALL" instead of "MANY". this is why I did not pick this one.

Moreover, what if there are other civilizations where there's only a few farmers using the new technique, what if the MANY is concentrated in one region, that civilization can still fail?

Also What's "MANY" means in these questions?

The correct answer choice is the one that "most weakens" the archaeologist's argument. So, we don't need an option that proves that NO modern civilization will EVER experience a similar fate. Instead, we just need the option that weakens the argument more than the other ones do.

The archeologist thinks that modern civilizations that rely on irrigation are likely to collapse because of a build up of toxic salts. (C) tells us that many modern civilizations that rely on irrigation have resolved the toxic salts issue. So, are these societies still likely to collapse for this reason?

They are certainly not as likely to collapse as it seemed before we knew this information. The word "many" in this context just means "a large number" -- so, a large number of modern civilizations have figured out a solution for the toxic salts, and won't suffer the same fate as the Sumerians.

Now, is it possible that some modern civilizations still have an issue with toxic salts, and will collapse? Sure! "Many" doesn't mean "all" -- but again, we don't need to prove that ALL modern, irrigation-based societies will be fine. Instead, we just need to weaken the conclusion that these societies are likely to collapse for this reason.

(C) does exactly that by showing that the salt issue isn't as big of a problem for many modern societies as it was for the Sumerians.

I hope that helps!

I was solving the question and end up with C and E. How to choose which one is most correct.

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CONCLUSION - Modern civilizations that rely heavily on irrigation are likely to fall

GIVEN -

1)Sumerians depended on irrigation
2) Irrigation led to toxic salts development in the soil as a result, the soil became unable to support agriculture
3) Sumerian civilization collapsed

WEAKNER- What new information reduces the belief in the conclusion?

ANSWER CHOICE ANALYSIS -

A) Irrelevant to conclusion
B) Factors unrelated to use of irrigation - not talked in the passage
C) CORRECT
D) Opposing the premise stated in the argument
E) Sumerians are not mentioned in the conclusion

weaken : toxicity ain't happening --> soil will not be damaged --> irrigation and agriculture all fine --> modern civilization wont collapse !

A. Most modern civilizations could not feed themselves through agriculture without relying heavily on irrigation : NOT CONCLUSIVE
B. Factors unrelated to the use of irrigation would probably have caused Sumerian civilization to collapse sooner or later : OUT OF SCOPE
C. Many modern farmers use irrigation techniques that avoid the buildup of salts and other toxic impurities in the soil : CORRECT
D. Many modern civilizations don't rely to any significant extent on irrigation for agriculture : IRRELEVANT
E. The soil of ancient Sumerian already contained some toxic salts and other impurities before the Sumerians started using irrigation for agriculture : OUT OF SCOPE