Although fullerenes - spherical molecules made entirely of c

[mafcostanza]

What is the difference between D and B? Why is D the OA and not B? Is B wrong because it says "some"?
Thanks.

(b) is wrong because it's irrelevant.

the point is that fullerenes occur in nature. if the naturally occurring fullerenes are like the ones manufactured in the lab, then we can infer conclusions about the state of the primeval earth.

the occurrence of fullerenes elsewhere - even if they're found on the shelf of the local grocery store - does nothing to undermine this connection.
nothing.

--

choice (d), on the other hand, basically says "hey man, the natural fullerenes and the lab fullerenes are apples and oranges."

Hi Ron-
I am almost there, I want to make sure my thinking is correct before I move on.

Originally, I thought B was correct because it attacks the premise that fullerenes are "found in nature, formed in fissures of the rare mineral shungite". I figured that B was saying something like 'hey maybe the fullerenes found in nature were not from nature after all, maybe they were from outer space and just fell to earth' and thus I figured that the conclusion was weakened because then the "laboratory synthesis of fullerenes" could not tell us anything about the state of the Earth's crust since the fullerenes came from space and were not formed in the Earth's crust.

However it seems that you are saying that we just have to accept the fact that the naturally occurring fullerenes are in-fact natural. And since you say B is totally wrong, is it correct for me to reason that to weaken a problem I have to accept the premises as given and focus on weakening the conclusion? Was it a mistake for me to think that I can weaken the conclusion by casting doubt on the premises?

[RonPurewal]

If something is given as a fact, then it's not a lie. If stuff is found in nature, then it's found in nature.

If a passage makes claims, then of course you can attack those. (If you have to "weaken" something, then you'll have to attack some claim made somewhere in the passage.)

But, attack facts? Nope.

[RonPurewal]

This idea has no bearing on choice B, either. If stuff is found on earth, that certainly doesn't mean it can't be found elsewhere, too. (Water and minerals occur naturally on earth, but there's also water on Mars, and there are minerals in just about every other star or planet.)

More importantly, the passage basically deals with the idea that Earth conditions are like lab conditions. Regardless of whether B is true or false, it's irrelevant to that comparison.

[RonPurewal]

Was it a mistake for me to think that I can weaken the conclusion by casting doubt on the premises?

One more thing. (If you are not at least somewhat nerdy, you can feel free to skip this post.)

Even if an argument's factual premises were preposterously false, it ultimately wouldn't matter here, because we're dealing ONLY with the validity of arguments"”i.e., NOT with the actual truth or falsity of the statements.

E.g.,
I, Ron Purewal, was born on January 1, 1914. Therefore, I am 100 years old.
This is a valid argument.
Both statements happen to be completely false"”but that does not invalidate the argument. Not at all. Because the conclusion still follows from the given "fact".

Again, this is really just "nerd discussion". The GMAT is not going to give you "facts" that are false, absurd, or counterintuitive. (There are never any "trick questions" on this test"”one of the principal reasons why it's a respectable test.)
But, even if they theoretically were to do so, there would be no impact on a question about strengthening/weakening/evaluating arguments.

[RichaChampion]

If something is given as a fact, then it's not a lie. If stuff is found in nature, then it's found in nature.

If a passage makes claims, then of course you can attack those. (If you have to "weaken" something, then you'll have to attack some claim made somewhere in the passage.)

But, attack facts? Nope.

hello ron sir I had an assumption so far that in weakening question we have to attack the conclusion, but this is quite strange that premise, which is a stated fact can also be attacked.

Their is one official question I belive it couldn't be posted here. This is what one Manhattan instructor has to say. Click Here.

[RonPurewal]

...and that's another one of the 12,895,746,217,805 reasons why you should just approach these with your own everyday common sense, rather than with memorized "rules" that will inevitably break down in random situations.
(:

NEVER forget—CR is intended to be something that you can just walk in, sit down, and do, using nothing except your own everyday human intuition and reading ability.
you DO NOT need any kind of "special knowledge" to do it—and, if you go around memorizing "rules" like this, that's just going to end up hurting you in the end.