Logging industry official: Harvesting trees from old-growth forests fo

But if it can only contain less than half the old tree's amount of CO2, then even though it absorbs CO2, it will not be able to absorb the amount released by the old trees...

I answer is B. I didnt like any of the answers very much. I ended up choosing A because of the phrase "which of the following if true"

I guess the B says the old trees are usless because most of the organic material is unsuable as lumbar. ( what an assumption ) The testmakers also need to know that trees are used for making paper and not just as lumbar. In that case B falls apart. The organic material might as well serve as wood pulp for making paper. The argument just uses word manufacture. It could mean anything.

Your comments will be appreciated.

Looks like stoolfi, praetorian123, dj are sleeping. stoolfi might avoid me because I press for explainations.

B is best...if the unused lumber is going to decompose anyway..whats the point of cutting the old trees in the first place?

A is out of scope
C supports the argument...if less Carbon is contained in young trees, it supports the cutting of old trees to be replaced by young trees.
D...supports the argument
E..doesnt matter if it takes a year or ten years...its out of scope

It is not unusable lumber. It is unusable as lumbar. I think there is a big difference between these two sentences.

I am leaning more towards B, but i'm not sure about it.

Although most of the points have been covered above, We can eliminate C, which is the most debatable one, on the basis of two things.
Firstly We are given that new trees soak up more CO2 from the environment than old trees soak up, we should not be concerned what the tress do with the CO2, maybe they make food out of it, maybe they utilize it in some other way.

Secondly Why should we assume that new trees that would replace the Old forest trees will be of same species.

Hope this is of some help

if b is true that means if organic matter cannot be used as lumber and will decay(bcoz it is made into products that decompose rapidly). but it was gonna decay in the forest anyway(but some matter would be used as lumber).

if c is true that means that the young trees will contain only half co2 as that of old trees so there is no benefit in harvesting the old ones.

Need expert's help (any anybody else too for that matter).

On the GMAT, a choice that introduces an idea suggesting that a plan will lead to another problem (A) in this example) can be correct. How do we distinguish between those choices and shell-game answers (that are incorrect)?

GMATNinja AndrewN

Hello, CEdward. As LSAT logical reasoning questions go, I thought this was one of the more straightforward ones, akin to a GMAT™ CR question. I have heard the term shell-game answer in reference to the CR Bible, so if you have that resource, you should have plenty of insight into your own question. Regarding my own approach to CR passages, and to answer your question in my own way, I always look to follow what I call the linear logic, and I keep my thoughts centered on the question itself. In this case, to weaken the argument, we need to be able to identify exactly what that argument may be. To put it simply, the logging industry official says that harvesting old-growth trees reduces carbon dioxide in the atmosphere. The first sentence puts forth the claim and offers support for it in the since clause, although we have to understand that harvested trees are removed from the forest for the pieces to fit; the second sentence offers further support—notice the transition moreover. To weaken the argument, then, we need to attack this notion that harvesting old-growth trees necessarily reduces levels of carbon dioxide in the atmosphere.

Choice (A) is an unrelated concern. Unless animal species can in some way be tied into the atmospheric carbon dioxide cycle, we cannot make heads or tails of the information presented. For this sort of answer to be correct, the question frame would need an adjustment, and that is the best answer I can think to give to your query. Read the passage, question, and answer choices carefully before you commit to anything, and focus on disproving answers as you comb through the options.

Meanwhile, choice (B) is the only one that attacks the heart of the argument. If the organic matter from harvested old-growth trees—the same trees on which the argument is based—that is not turned into lumber is made into products that decompose rapidly, then from what the passage tells us in line one, we would expect such decomposition to contribute to increasing carbon dioxide in the atmosphere, regardless of the net change. (Yes, the argument could still hold, but this new consideration allows us to appreciate that the picture might not be as grim as the one outlined in the passage.)

That is as far as I took my thoughts on these two answers. I hope the above analysis may prove helpful to you. Thank you for thinking to ask.

- Andrew

OK so I gather, that more often that not, sticking to the conclusion as closely as possible, word for word even, is the ideal route.

A follow-up question, if I may. Often times we see answer choices of the shell-game variety that I mentioned that specifically start with 'some...' and are framed in the negative / opposite of what the passage says (see E) in this example here: https://gmatclub.com/forum/speaker-cont ... l#p2770784)

My question is: why are those types of choices fundamentally wrong?

So, the conclusion is Harvesting old-forest trees => reduce Carbon Dioxide.

Two reasons:
Large old trees die => decompose => release carbon dioxide
young trees => absorb more carbon dioxide than old trees => making space for new trees will reduce carbon dioxide.

Think about the underlying assumption first:

Assumption is old trees when harvested and manufactured will not produce Carbon Dioxide. This will help you reach answer quickly, as the weakner will attack this assumption.




Totally Irrelevant.


This weakner is attacking the assumption, it says that even if we manufacture most of the organic matter from old trees will decompose rapidly, and decomposition leads to carbon dioxide.


It is an additional information, which pretty much support and strengths the argument.

This information is a strengthener, it pretty much gives same info as given in the stimulus.



[/quote] Irrelevant.

Hello again, CEdward. I worked on that other question you linked to, and indeed, if you know how to spot the some trap, you can quickly determine the correct answer. So what is wrong with some, exactly? Nothing that I would call a fundamental issue, to be clear. But the majority of the time it is used in CR, it is vague to the point of having no bearing at all on the argument. For instance, if I am trying to make a case that passion fruit (one of my favorites) is gaining ground on (or becoming more popular than) other citrus fruits, and your task is to weaken that argument, what good would it do to say that some people prefer oranges, or even that many people buy oranges exclusively whenever they purchase citrus? We simply cannot pin down what these quantifying words mean in the context. Some or many could be more than one or several, respectively. But if we are talking about a thousand people, then what difference would it make if ten of them preferred oranges? We simply have nothing to lean on, so we cannot get behind such an unqualified some. (Note that most is different, for just the reason you would expect.)

Now, can we say that you should write off any some answer? Absolutely not. Two official questions come to mind immediately:

1) To reduce traffic congestion...

2) Ramirez: The film industry claims that pirated DVDs...

It is probably no coincidence that both of the above questions are rated 700-level. Perhaps too many people are looking to create a hard rule without really engaging with the passage. You simply have to consider the context in which some appears, and, as always, your goal should be to narrow the answer pool down to the one option that is hardest to argue against.

I hope that helps with your follow-up question. Good luck with your studies.

- Andrew

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