Q21 - Mark: Plastic-foam cups, which contain

[ebb5bdffdf]

Can we please go over this question? Why is D incorrect?

[ManhattanPrepLSAT1]

The simple answer to your question is that answer choice (D) doesn't weaken the evidence presented by Tina. It may challenge her conclusion, but not her evidence. So don't forget to pay close attention to the question stem!

Answer choice (C) however attacks Tina's evidence about the quantity of energy it takes to produce the paper for paper cups. Tina's second sentence contains information from a study conducted 5 years ago. Answer choice (C) calls that evidence into question by saying that what was the case 5 years ago no longer is the case.

Let's look at the incorrect answers...

(A) would strengthen Tina's argument, rather than weaken it.
(B) is irrelevant. The issue is the environmental impact, not a relative comparison on the likelihood of paper cups and foam cups being accepted by consumers.
(D) undermines Tina's conclusion about the relative environmental damage of foam cups and paper cups, but doesn't address Tina's evidence.
(E) supports Tina's conclusion, but neglects her evidence.

Does that answer your question?

[vandyzach]

Hello,

I am trying to master LR and every time I think I make a gain by thinking about something in a different way, I end up being wrong. My question is: What is wrong with the following line of thinking:

(C) doesn't weaken (and is thus wrong) because we don't know if burning waste wood is better or worse for the environment than the negative effects of petroleum on the environment? What if burning waste wood is worse for the environment? Then this answer choice would be a strengthener. Thus, it is not a weakener.

Answer choice C seemed to me like a trap answer because of what we don't know about the negative effects of burning waste wood.

[WaltGrace1983]

Hello,

I am trying to master LR and every time I think I make a gain by thinking about something in a different way, I end up being wrong. My question is: What is wrong with the following line of thinking:

(C) doesn't weaken (and is thus wrong) because we don't know if burning waste wood is better or worse for the environment than the negative effects of petroleum on the environment? What if burning waste wood is worse for the environment? Then this answer choice would be a strengthener. Thus, it is not a weakener.

Answer choice C seemed to me like a trap answer because of what we don't know about the negative effects of burning waste wood.

I don't think that there is necessarily a problem with your thinking but I think that sometimes it helps just to think about the "best" answer in these situations. You're absolutely right; we do not know much about the environmental effects of burning waste wood. However, look at the function of (C).

(C) is saying "Okay Tina, I see your point and you are right. The production (what is talked about in Tina's first premise) and the transportation (what is talked about in Tina's second premise) does cause serious environmental pollution." In other words, Mark is conceding Tina's point and saying that she is right. However, when Mark says that "the energy that runs paper mills now comes from burning waste wood rather than petroleum," he is basically saying that her point is moot and doesn't lead to the conclusion.

What is our task of a weaken question? We are supposed to show that the premises of an argument don't necessarily lead to the argument's conclusion. In most cases, the weakener will do exactly what (C) does. It will say, "yep that premise certainly is valid but here is something you forgot about!" It is not meant to completely contradict the argument and prove why the argument is 100% wrong. It is, instead, supposed to show how an argument can be doubted. (C) does this in a way that, as you said, is rather weak but still gets the job done.

If that answer doesn't satisfy you, you can also think about it as a search for the BEST answer. Sometimes strengtheners/weakeners are very unfulfilling. You can look at the other answers and eliminate those first.

(A) We already know about the manufacturing of paper and how it apparently is bad. We don't need to add further detail to this. We instead need to add further detail to the connection between Tina's premises and argument: we need to show that her premises don't necessarily lead to the conclusion. This just bolsters the premise.

(B) We don't care about consumers think. We are talking about cold hard facts!

(D) I actually think this weaken's Mark's initial argument (that Styrene is generated in foam production and persists indefinitely) by showing that - even though this is true - it doesn't make a big impact. It also defends Tina's argument a tiny bit rather than fulfills our job, to weaken her argument.

(E) This also seems to weaken Mark's argument a tiny tiny bit because it shows the benefits of leaving forests uncut. We need to cut down forests to make paper for the cups. However, if there are LESS environmental benefits for cutting down forests than leaving them uncut, this isn't good for Mark.