RC Question 3 Explanation
DISCUSSION: This question stem is quite clear. The passage literally answers one of the questions. You should practice quickly locating information in the passage: it can let you get questions like this with 100% certainty.
I don’t memorize facts when I read a passage, but I do take note of them. It helps when doing a question like this: you can quickly dismiss some answers as likely wrong, and you can also locate information more quickly if you remember roughly where it was.
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- The Brazilian Amazon is only mentioned in lines 16-17, and the author doesn’t say what percent of the forest is there. The only “percent of forest” mention in the passage is the fact that commercial forests are 3% of tropical rain forests.
- This is a trap answer. It’s true that lines 48-49 say plantations are designed to produce wood and wood pulp. But this answer says how many products are derived from plantations. Derived means “comes from”, no matter how long the chain is. So if paper comes from wood pulp made on a plantation, then paper is “derived” from the plantation.
There are countless products made from wood pulp and we have no idea what their total is. - CORRECT. Line 22 in the middle of paragraph 2 says that trees produce oxygen by photosynthesis.
- This isn’t in the passage, and it’s unlikely it would be. The author’s point is that, on balance, forests don’t produce oxygen (because trees consume oxygen when they die). So this answer doesn’t make sense in light of the author’s argument.
- We don’t know. Carbon dioxide is only mentioned once, in lines 18-19. The author spends more time talking about oxygen. (Though they don’t make this comparison for oxygen, either)
This confused me because the only thing the passage says is “Trees do produce oxygen by photosynthesis” and apparently thats enough to answer the question “by what processes do plants produce oxygen?”. I know that trees are a type of plant, but it’s still just only one type of plant, and there’s probably thousands or even millions of types of plants. Does saying trees produce oxygen REALLY answer the question of how do plants produce oxygen??
I feel like this is a logic error that would never fly in logical reasoning.
Johnny knows how trees make oxygen. Therefore, Johnny knows how plants make oxygen???
Am I misunderstanding something grammatically? Shouldn’t it be ‘some plants’ or ‘at least one type of plant’? If it’s just ‘how do plants make oxygen’ doesn’t that mean much more than just one type of plant?
The question stem doesn’t say ‘partially answer’, it says “the information in the passage *answers* which of the following question”…. so it doesn’t have to answer the question completely or definitively….? Like whats the takeaway here?
Please help, because I don’t want to have a misunderstanding that I repeat :(
It’s best not to be fussy about LSAT answers. The instructions just ask you to find the best answer. You haven’t got any misunderstanding, and indeed the question only provides a partial answer. However, trees are the largest plants by far. Also, B does suggest that there is only a SINGLE process by which plants produce oxygen. Since trees use photosynthesis, that suggests that this is the single process used by all plants. LSAT answers are quite literal and can support inferences.
Finally, you may know from outside knowledge that other plants also use sunlight to grow. This isn’t strictly a criteria in judging RC answers. But if an answer appears to be the best, and it conforms to outside knowledge rather than contradicts it, you can feel pretty safe in picking it.
Hope that helps!
I got this question right but not without some serious consideration. My confusion came mainly from answer choice B. Ive looked in various places and no one is talking about how the second sentence of the passage literally mentions “5,000 commercial products produced from forests”. Can you explain to me how this doesn’t help B’s case??
I can help there :) So, the LSAT is all about key conceptual distinctions. You flagged an important sentence, but it refers to products derived from forests, e.g. natural forests.
Whereas B talks about commercial plantations. Groups of trees or plants managed by humans which aren’t forests. B is a definite trap and probably was written to target the exact sentence you highlighted. Thanks for asking, it’s a great question. Hope this helps!