Q14 - Reducing speed limits neither

[ocho34]

Came down to choice (D) and (E).
Is (E) wrong because of the conditional term "only if"?

[aileenann]

Yes, that is definitely one reason that (E) is wrong.

I'd say that another problem is "significant" - the argument is about risk in general not just "significant" risk.

[mrudula_2005]

if E was rewritten to say "presumes, without providing justification, that drivers run a risk of collision if they spend a lot of time on the road" would that be correct? or does the argument not presume anything related to that without justification because it does say that during the extra time spent on the road the car "spews exhaust into the air" - so would that count as sufficient justification?

Also, why is D correct? the argument talks about emissions but never talks about total emissions (just as it talked about risk but did not talk about significant risk as stated in E) and as far as I could tell never indicated that those emissions are determined primarily by the amount of time the trip takes...it merely cited a correlation...

thanks in advance for your help!

[aileenann]

Ok, as to your first question: "if E was rewritten to say "presumes, without providing justification, that drivers run a risk of collision if they spend a lot of time on the road" would that be correct?" I think this answer choice would still not be correct. I say this because it begins to look more and more like the very premise that the argument uses in its core that the more slowly a car is driven, the more time it spends on the road running the risk of colliding with other vehicles. Granted, it isn't quite the same, but it's close - much more of a premise booster than an assumption.

Another way to get rid of this is entirely different - there's a scope issue. We only care about what reducing speed limits does. We don't care about the other risks for collission that are undiscussed.

Now, to your second question - why (D) is the answer. It's not as direct as some other LSAT questions, but I think what the answer choice is getting to is the author using evidence that emissions will go up as vehicles spend more time on the road. This ignores the fact that, for example, speed might also play into emissions. When the argument ignores these other ways of increasing emissions, it opens itself up to criticism (or makes an assumption) regarding whether lowering the speed limit really lowers emissions. The word "primarily" is alright here because the author does seem to be taking the time a car spends running as a proxy for the most important kind of/biggest concern about emissions.

Does that make sense? Let me know if you have follow-up questions or concerns

[LSAT-Chang]

After reading the above explanation.. I still don't like answer (D) and I don't see why (B) wouldn't be the correct answer. In the strategy guide, it just says B is out of scope. Could you provide me more detail as to why (B) is wrong? I follow the suggested steps to solving these types of problems.

The two main things I always consider just to help me find gaps are: is there a mismatch between the premise/conclusion AND/OR is the author not considering other facts that needs to be considered in order for the conclusion to hold?

So when I was solving this problem, when I came to (B), I was very confident that it was the correct answer because the other isn't considering possible benefits from reducing speed limits other than environmental and safety benefits. OHHHHH.. wait a second.. since the author's CONCLUSION is: "reducing speed limits neither saves lives nor protects the environment" and doesn't conclude about anything other than environmental and safety benefits, the author's reasoning can't be flawed for not considering other benefits since the author doesn't even conclude anything about them! Right??? Please let me know if this is the reason why (B) is wrong and perhaps makes sense that it is out of scope.

So anything that doesn't relate to the author's conclusion should be just eliminated right? But wouldn't (D) also not relate to the author's conclusion? Maybe this is not the right way to solve these problems.. please help!!

[bbirdwell]

The two main things I always consider just to help me find gaps are: is there a mismatch between the premise/conclusion AND/OR is the author not considering other facts that needs to be considered in order for the conclusion to hold?

The first one sounds great. The second one I'm not sure about. In addition to premise/conclusion mismatch, I also look for common flawed argument forms (analogy, proportions, causal, etc.).

OHHHHH.. wait a second.. since the author's CONCLUSION is: "reducing speed limits neither saves lives nor protects the environment" and doesn't conclude about anything other than environmental and safety benefits, the author's reasoning can't be flawed for not considering other benefits since the author doesn't even conclude anything about them! Right???

Exactly. If I argue that "sometimes elephants are purple," it doesn't matter whether dolphins are sometimes purple. Always stick to the author's actual conclusion...

So, in this example, I would find the core.

C: reducing speed limit doesn't save lives, doesn't protect environment

p: more slowly a car moves, the more time on the road spewing exhaust and running the risk of collision

This one's tough. Notice that the conclusion is basically two separate things: ~lives AND ~environment. We need to check the evidence to see if both of those are supported. Hmm.

It's a pretty tight argument. The one thing that seems to be assumed is the relationship between time and the unwanted outcomes: "more time spewing exhaust" = "more bad for environment" and "more time on road risking collision" = "more bad for lives."

I could imagine cases where driving faster burned more fuel and was thus more polluting, or where driving faster was a greater contributor to risk of collision than time spent on road.

Primed to look for an answer that brought attention to the "time" concept, I'd go to the answers.

(A) nope. Even if this fact is considered, it seems to support the conclusion.

(B) for the reasons you stated above, we can safely eliminate this out of scope choice as soon as we see "other than..."

(C) again, like (B), even if considered, this fact seems to support the conclusion

(D) ah, time. Yep. Notice how this answer choice is phrased as an assumption (presumes = assumes). This means we can even use the negation test to double check. If emissions are NOT primarily determined by the amount of TIME a trip takes, this argument loses the one piece of evidence that it's standing on.

(E) eliminate as soon as we read "only if."

[LSAT-Chang]

The first one sounds great. The second one I'm not sure about. In addition to premise/conclusion mismatch, I also look for common flawed argument forms (analogy, proportions, causal, etc.).

I actually got the two from the LR strategy guide Ch 4, which says:
The right answer to any Identify a Flaw question will address one or both of the following concerns:
1. is there a premise/conclusion mismatch?
2. what other factors has the author failed to consider in reaching his conclusion?

Did I misphrase the second part of it? Or are you saying you don't agree so much with the second one?

[bbirdwell]

It's true that many correct answers point out something that the author fails to consider. This is why you see the phrase "fails to consider" or "neglects the possibility" in so many flaw question answer choices. I think the guide is just pointing out that this is often a characteristic of correct answer choices.

What I'm saying is that I don't think there's a need to spend much effort trying to predict what the author has failed to consider. Either you see an obvious gap/mismatch, you see a common flaw, or you don't. There might be five dozen relevant factors that the author has failed to consider. Trying to predict them up front, which is what I thought you said you were doing, sometimes works, and is often a lost cause.

Now, I have no familiarity with your actual thought process, so I'm just pointing this out in case it's helpful. It's very common for people to take a very imaginative approach to predicting what the author hasn't considered, and this is very often counter productive. Analysis is better than imagination on the LSAT.

[mcrittell]

1) Why would "only if" disqualify E as a credited response? (I know it's a necessary signifier)?
2) I'm still not understanding the diff btwn D and E

[bbirdwell]

(D) and (E) are similar in that they both involve the concept of TIME, which is essential to the argument.

For (E), the author simply does not do this. Nowhere in the argument does it say that spending a lot of time on the road is the ONLY way that drivers run risk. For all we know the author would agree with the idea that drivers run risk when they are drunk, when they are tired, when they are driving go-carts on the interstate, etc.

(D) says "emissions PRIMARILY determined by TIME." This is exactly how the author reasons: environment not protected by lower speed limits b/c slow = more time spewing exhaust.

Note that this answer is an assumption ("presumes" = "assumes"). So if we're feeling fancy, we can negate it. What if emissions are NOT determined by length of time? A major part of the author's argument fails. Therefore this is the best answer.

[romanmuffin]

I have a question about the negation of D: Doesn't the fact that "total emissions are not determined PRIMARILY by the amt of time a trip takes" imply that time still plays a role in determining emissions? I feel the author never talks about the primary reasons, but rather just states the connection in a neutral way. Thus, the negation of D won't weaken the argument.

[gmatalongthewatchtower]

Teachers,
I am not sure why A) is incorrect.

I feel that A) hinges on a minor gap in the argument :

Premise talks about "more slowly a car is driven .... " but the conclusion is about "reducing speed limit ". I feel that A) is trying to attack this gap. Essentially, just because the speed limits are reduced, the drivers won't have an incentive to drive slowly. If there are some drivers (In LSAT World, some means at least 1 - hence, "some" could mean all) don't follow speed limts. (In fact, I don't follow speed limits every time:))

I am not sure why A) is incorrect in such a case. Please help me

Thanks

[nflamel69]

Not sure if this has been addressed or not, but I eliminate E also because it said a lot of time on the road. How much time is a lot of time? We only know they spend more time, but does it quality as a lot?

[tommywallach]

There are three questions that have been asked (some of them a LOOOOONG time ago). I'm going to quickly take on all three.

I have a question about the negation of D: Doesn't the fact that "total emissions are not determined PRIMARILY by the amt of time a trip takes" imply that time still plays a role in determining emissions? I feel the author never talks about the primary reasons, but rather just states the connection in a neutral way. Thus, the negation of D won't weaken the argument.

I think this is more plain logic. Obviously, the amount of time you spend in a car MUST affect emissions in some way (if you spend no time in a car, versus 12 hours in a car, for example). So (D) can only say it's not the primary determinant of emissions, implying that the argument up above (that there's no ecological benefit to driving slowly because you spend more time on the road) could very well be wrong. If some other factor has a larger effect on emissions, then who cares about the time on the road?

Teachers,
I am not sure why A) is incorrect.

I feel that A) hinges on a minor gap in the argument :

Premise talks about "more slowly a car is driven .... " but the conclusion is about "reducing speed limit ". I feel that A) is trying to attack this gap. Essentially, just because the speed limits are reduced, the drivers won't have an incentive to drive slowly. If there are some drivers (In LSAT World, some means at least 1 - hence, "some" could mean all) don't follow speed limts. (In fact, I don't follow speed limits every time:))

I am not sure why A) is incorrect in such a case. Please help me

Thanks

So the first problem with (A) is exactly what this student mentioned. "Some" means very little on the LSAT. "Some" could literally be two people. Two people are not going to have any effect on this argument. Also, when people ignore the speed limits, are they going too fast, or too slow? We don't actually know how this would affect the time spent on the road. (I know, you're thinking it's obvious that people go faster than the speed limit. But the argument doesn't say so...)

Not sure if this has been addressed or not, but I eliminate E also because it said a lot of time on the road. How much time is a lot of time? We only know they spend more time, but does it quality as a lot?

Yes, I think this issue has been addressed. The problem is really the conjoining of "only" and "a lot of time." The argument never presumes that you can only get in a collision of you spend a lot of time on the road. What it does presume is that you're more likely to get in a collision if you spend more time on the road (which is an error, in my opinion, because spending more time on the road at a lower speed might be significantly safer than spending less time on the road at a higher speed).

Hope that helps!

-t

[Aquamarine]

I still have questions about (B) and (D)

First of all, an answer choice like (B), "ignore the possibility of benefits from lowering speed limits other than environmental and safety benefits.
I can see sometimes it's a right answer because a flaw is an author doesn't consider other factors except for the factors mentioned in a stimulus. But sometimes it's a wrong answer because it's out of scope just like Q.14.
So I can't really find out what kind of stimulus should be if an answer choice like (B) is a right answer.
Whenever I encounter an answer choice like (B), I'm always stuck.

Lastly, about (D), how is it still a right answer? Shouldn't it say both saving lives and protecting the environment just like the author says and Brian's explanation above?
I mean it only says about "protecting the environment" and doesn't say about "saving lives". So that's why I entirely don't understand why D is an answer.

Can anyone explain me?
Thanks!

[WaltGrace1983]

[LSATGeek comment: Post edited for thread clarity.]

Lastly, about (D), how is it still a right answer? Shouldn't it say both saving lives and protecting the environment just like the author says and Brian's explanation above?
I mean it only says about "protecting the environment" and doesn't say about "saving lives". So that's why I entirely don't understand why D is an answer.

I thought the same thing. However, the flaw doesn't have to completely solve the argument. Solving one portion of the argument is fine (i.e. pointing out the flaw). Many hard questions like this one have multiple flaws. One correct answer won't address ALL the flaws yet if it addresses at least one then it should be correct.

[WaltGrace1983]

I may make a thread in the General LR questions forums if no one has any thoughts on this but I just noticed something about (A).

I thought (A) was a VERY tempting answer. Yet Tommy said above that it is wrong because of the word "some," as "some" is a very weak word that doesn't do too much to this argument. I agree with that but am still not wholly satisfied as the conclusion is very strong. I was thinking that maybe there was something more. I think (A) would still get at a very valuable disconnection between "the more slowly the car is driven" and the idea of a "speed limit."

What I mean is that maybe it is true that the more slowly a car is driven the more time it takes putting exhaust in the air while it is not true that reducing speed limits doesn't protect the environment.

(A) says that the argument neglects the fact that some motorists completely ignore speed limits. How about this reasoning: there is no "fact" in the argument. We don't know what is "fact" because the stimulus gives us only a few facts - none of which relate to how many people ignore/don't ignore the speed limit.

Is there a difference between neglecting a fact and neglecting a possibility? In most flaw questions, it neglects the possibility and this has very different connotations (in my head) than neglecting the fact. A fact must be supported - a possibility is a hypothetical.

Is this a nice breakthrough or superfluous thinking that will never help me ?

[lsatzen]

Thought I would post my reasoning for (A) and (D). Can someone verify my reasoning?

I eliminated (A) because, even if he/she considered it, it would strengthen the conclusion. If some motorists completely ignore speed limits, then it seems to add evidence for the conclusion that reducing speed limits neither saves lives nor protects the environment. I understood it as implying that there are some people that simply do not even pay heed to the sign, which means it [speed limits], in some cases, aren't really doing anything at all - in regards to saving lives or protecting the environment.

It would be like saying: "The surgeon general's warning on cigarettes does not save lives" and someone trying to counter that statement with "Well, you overlook the fact that some people don't even look at the warning". In this case, I think it is more evident why it would be a potential strengthener. Further, this objection is actually compatible with the conclusion.

As far as (D) is concerned, I think this assumption warrants the use of "primarily". Looking at the conclusion (re-phrased to pertain only to (D):

C: Reducing speed limits does not protect the environment.
P: More slowly a car is driven, the more time it spends on the road spewing exhaust into the air.

Analysis: It is fair to grant that the more slowly a car is driven, equates to more time spend on the road (consider MPH), and thus more time spent on the road spewing exhaust into the air (but how much exhaust? Is time the only factor in determining amount of exhaust?). Taking these statements at face value, he concludes that this does not protect the environment. In order to conclude that, he must be assuming that more time = more exhaust. But what the author fails to consider is that there could be other equally relevant factors that determine the total amount of exhaust released, for example, speed (as others have mentioned). What if driving more slowly + spending more time on the road actually reduces the amount of exhaust released, as compared to driving faster + spending less time on the road?

Accordingly, because the author has neglected to entertain these other plausible alternatives, he is presuming, without providing justification that "total emissions for a given automobile trip are determined primarily by the amount of time the trip takes". In other words, the "presuming, without providing justification" is referring to the fact that the author has not sufficiently established that time is in fact the primary / most significant factor, because, via the hypothetical situation above, we showed that other factors could play a determinative role in establishing how much exhaust is emitted.

[christine.defenbaugh]

Spot on, lsatzen!

(A) would be a rockstar flaw for an argument that was suggesting that we SHOULD lower speed limits, based on a premise that driving slower is better in some way. That argument would be assuming that speed limits actually alter the behavior (speed), and as a result, would be flawed by ignoring all the people that drive faster than the speed limits.

But this argument is concluding that the speed limits don't help anyone. Even if ALL the motorist ignored the speed limit, that wouldn't undermine that conclusion at all - if people ignore them, then they sure aren't saving lives!

Keep up the great analysis!

I'd like to address another question while I'm here:

I still have questions about (B) and (D)

First of all, an answer choice like (B), "ignore the possibility of benefits from lowering speed limits other than environmental and safety benefits. I can see sometimes it's a right answer because a flaw is an author doesn't consider other factors except for the factors mentioned in a stimulus. But sometimes it's a wrong answer because it's out of scope just like Q.14. So I can't really find out what kind of stimulus should be if an answer choice like (B) is a right answer.
Whenever I encounter an answer choice like (B), I'm always stuck.

The simplest way to think about this is whether the 'other factors' are 'other than factors in the premise' or 'other than the factors in the conclusion'. If we're raising factors other than those in the premise, and the 'other factors' have an impact on the conclusion - they're totally relevant! However, if they are factors other than those in the conclusion, then we don't care at all - out of scope!

For instance, if I argue that this herb is good for you, because it has Vitamin A, I'm ignoring all the other things the plant might have other than Vitamin A that might make the herb NOT good for you. The premises only tackle Vitamin A, but other things may matter for the conclusion of 'good for you'.

However, if argue that this this plant will improve your eyesight, because it has Vitamin A, then it does not matter what other health effects the plant has other than eyesight. Eyesight is all the conclusion cares about; anything else is out of scope.

Does that help clear things up a bit?

[skela]

The "primarily" in D seemed bad to me because what if the author meant "the more slowly a car is driven, the more time it spends on the road spewing exhaust into the air...ALL ELSE BEING EQUAL." Like say you've got a Prius and some high-emission vehicle. So then the primary factor in total emissions is the type of car; the Prius is going to emit less than the high-emission vehicle, but the Prius driven for a longer period of time could emit more than the Prius driven for a shorter period of time. So the author's conclusion could still make sense even without presuming trip time is the primary factor in determining total emissions