Q23 - In modern "brushless" car washes

[panman36]

Just don't really like "C" that much. I had to take forever before selecting it after deciding all the others were worse.

I know it says "mitters are easier on most cars' finishes than brushes are." But to me that could mean that mitters leave fewer visible scatches, or that the scratches are more faint but still visible. From this I wasn't convinced that modern "brushless" car washes usually do not produce ANY visible scratches on cars with older finishes as "C" says. That's why I had such a difficult time selecting it. Am I missing anything? thanks

[ManhattanPrepLSAT1]

Remember that "most strongly supported" does not mean "can be inferred." You don't need to prove anything on this sort of question. You just need to find an answer choice that enjoys more support than the other answer choices.

We know that mitters are easier than brushes on the finish of a car, and this is especially important when it comes to producing scratches on cars with clear-coat finishes. That sounds to me like mitters produce less scratches than brushes.

Also, the answer choice doesn't say that mitters do not scratch cars. It says that mitters usually do not produce visible scratches. That's not quite as strong as you put it.

I wasn't convinced that modern "brushless" car washes usually do not produce ANY visible scratches on cars with older finishes as "C" says.

Does that answer your question?

[sissixz]

Why not A?

I thought brushes are worse than mitters, so should be more scratched finishes...

[tamwaiman]

Why not A?

I thought brushes are worse than mitters, so should be more scratched finishes...

Because we do not know whether older-finishes cars are more than new-finishes ones.

[sissixz]

Thanks!!! I thought so.

[melmoththewanderer88]

I got this question correct, selecting C, but after rechecking everything, this question bothered me to no end.

Here is my process...

(A) We don't know enough about the distributions of old/new cars to support this. Eliminated.
(D) Quickly eliminated. Contradicts the stimulus.
(E) We have no information about the relative distributions of cars with whatever type of finish. Eliminated.

This left me with B and C, and to be honest, both of them seemed to me flawed.

B tries to imply that brushless car washes were introduced because of the advent of clear-coat finishes. We know they occur together, but we don't know that clear-coat finishes preceded brushless car washes.

C brings in the concept of visibility. Nowhere does the stimulus say anything about visibility. In fact, there is only a relative "easier on," which in the land of LSAT precedent does not imply easy (in fact, there is a flaw question in superprep that explicitly tests this concept).

If B was correct then you would assume that two things occur together are correlated and that correlation implies causation (and in fact, there is 1 most strongly supported question involving wheelchairs that takes correlation to imply causation).

C requires "easier on" to imply "easy" which would need to further imply "not producing visible scratches." This strikes me as too much of a stretch.

So I'm wondering what are the better grounds for excluding B in favor of C? And how is C even supported at all?

[ManhattanPrepLSAT1]

Hey melmoththewanderer88! Good question.

The first thing we should do is make sure we're answering the right question. We do not need to be able to prove the correct answer choice. We only need to find one that is "most strongly supported." Keep this distinction in mind when you work on Inference questions. When it asks for "what can be inferred?" or "what must be true" we need to find an answer choice we can prove. Here, all we need is something that is "most strongly supported."

Correct Answer
Since mitters are better for clear-coat finishes, they should be even better for older finishes. While we cannot prove "usually," there is strong support that mitters will be much easier on older finishes than newer ones - leading us to suspect that they usually don't leave scratches on older finishes. This one is all about the question stem!

Incorrect Answers
(A) is unsupported. Older finishes were less easily scratched than the new clear-coat finishes. Maybe they held up easily to the brushes before.
(B) is unsupported. This attributes the introduction of the mitters to the clear-coat finishes. We don't know why though the mitters were introduced, maybe they were just cheaper!
(D) is out of scope. We aren't given any information on how effective at cleaning the two washes are. We only know which one is more likely to leave scratches.
(E) is unsupported. No information on the frequency of each type of finish on cars today.

#officialexplanation

[melmoththewanderer88]

That subject change in (D) went right past me, too!

This is wonderful, thanks for the post, Matt!

[tzyc]

I could not imagine what this situation is...
What does "mitters are easier on most cars' finishes than brushes are" mean?
Why if it's easier. it produces less scratches?
For some reason this stimulus confuses me a lot...
Thank you

[sumukh09]

I could not imagine what this situation is...
What does "mitters are easier on most cars' finishes than brushes are" mean?
Why if it's easier. it produces less scratches?
For some reason this stimulus confuses me a lot...
Thank you

Yup you have the interpretation right. So we have modern car washes that use these mitters instead instead of brushes; older cars scratch less easily than newer cars and we know that mitters are easier on most cars' finishes than brushes.

C says modern brushless car washes usually do not produce visible scratches on cars with older finishes which is a valid inference based on the information in the stimulus.

[enasni.me]

Why can't it be E...The stimulus says "This is especially important with the new clear coat finishes found on many cars today,..." so doesn't 'many' implies more cars in use today..

please explain. thanks.

[mshinners]

Why can't it be E...The stimulus says "This is especially important with the new clear coat finishes found on many cars today,..." so doesn't 'many' implies more cars in use today..

please explain. thanks.

Nope, it just means that we have some cars out there with new clear coat finishes. That's not very strong (it doesn't mean "most" - there are many people in America, but most people aren't in America), and it isn't comparative (so we can't say "more than").

[Mab6q]

Since mitters are better for clear-coat finishes, they should be even better for older finishes.

Based on what? For all we know they aren't better, but instead there's imply a small percentage of older cars, so car washes don't care about their needs as much. This was a pretty weak answer choice, even by MSS standards.

[andrewgong01]

Hey melmoththewanderer88! Good question.

The first thing we should do is make sure we're answering the right question. We do not need to be able to prove the correct answer choice. We only need to find one that is "most strongly supported." Keep this distinction in mind when you work on Inference questions. When it asks for "what can be inferred?" or "what must be true" we need to find an answer choice we can prove. Here, all we need is something that is "most strongly supported."

Correct Answer
Since mitters are better for clear-coat finishes, they should be even better for older finishes. While we cannot prove "usually," there is strong support that mitters will be much easier on older finishes than newer ones - leading us to suspect that they usually don't leave scratches on older finishes. This one is all about the question stem!

Incorrect Answers
(A) is unsupported. Older finishes were less easily scratched than the new clear-coat finishes. Maybe they held up easily to the brushes before.
(B) is unsupported. This attributes the introduction of the mitters to the clear-coat finishes. We don't know why though the mitters were introduced, maybe they were just cheaper!
(D) is out of scope. We aren't given any information on how effective at cleaning the two washes are. We only know which one is more likely to leave scratches.
(E) is unsupported. No information on the frequency of each type of finish on cars today.

I still think the LSAC/LSAT went too far with this oneafter reading it.

For "C"
First, it says "usually" and we do not know . More importantly, we never had any baseline in the entire stimulus on what the usual rate of scratching is. What if the scratching rate was always around 5% and the new brushes bring it down to 1% (i.e scratching was never really an issue) or what if scratching is a very common everyday issue that happens like 95% of the time but this new brush is so good that it dramatically drops scratching rates but scratching is still common like 57%. Hence, without any baseline indication it is hard to support usually. If this is an everyday common occurence maybe it still happens more than 50% of the time but it just is not as high as like 95%. In other words, if scratching is super common maybe the new brush doesn't change things by that much.

I chose "A". I think A would have been a perfect answer had it said something like proportion of cars on the street have less scratched finishes to purge out the effect that in general there are more cars today on the road . That aside, "A" seems supportable because we know that older brushes are bad for cars and caused scratches so we should expect less cars scratched on the street now (after we control for the fact that there are more cars on the street today and scratches due to other issues) . I see why "A" is not perfect for the reasons I listed but at the same time I don't really see it as "unsupported" or why "C" makes fewer inference jumps than "A"

Hence, I think the LSAC/LSAT over stepped the inference here...


The other choices, I agree, were easy eliminations:
B can be eliminated cause causality was never discussed. Perhaps the new brushes are cheaper to maintain and it was to help out gas stations increase profit margins

D we know nothing about what is more effective and maybe it is better for older cars too

E seems to play on the idea that it was because of more cars having fragile paint that car washes changed. Regardless, it is unsupported.

[NickC447]

One thing nobody's mentioned about answer choice (A) is that it's making an extremely broad, sweeping claim. It's not just talking about cars that may or may not have been scratched by car washes; it's talking about all the cars on the road, in general. It says "there were more cars on the road with scratched finishes than there are today."

It could be that, both then and now, cars are getting scratched left and right by tree limbs and door dings and the keys of jilted ex-lovers. So even if we knew what the ratio of new cars to old cars is, and even if we knew that brushes scratched the more resilient finishes of old cars, this would still be a huge jump to make. What's more, the one thing we do know that applies to cars generally (rather than cars that have been subjected to a car wash) is that many cars nowadays have more delicate finishes than older cars. So how could we possibly conclude from this that there were more scratched cars on the road back in the day?

(C), on the other hand, is relatively straightforward. It does require a bit of an assumption, but it's a pretty reasonable one. We have to make the leap that the gentlest type of car wash does not usually produce visible scratches on the most resilient type of finish. If we can't make that assumption, then we have to assume instead that both types of car washes regularly produce visible scratches on cars both old and new. And that's just sort of ridiculous.

[ghorizon09]

This question seems to be testing a concept Aristotle discusses in his book Rhetoric.

If a person would not steal from a stranger then that person would not steal from their Mother. If she would not do the lesser thing then she would not do the greater thing,

If new finishes are more easily scratched than older finishes, and mitters are more gentle and therefore more suitable for new finishes, THEN mitters should also not scratch older (tougher) finishes.

Simply put - it is easier to scratch the new finish than the old, and the mitters do not scratch the new finishes (or scratch less than brushes), THEN it is strongly supported that the mitters will not scratch the more-difficult-to-scratch-older-finishes.

[mswang7]

mitters have replaces brushers in modern car washers.
mitters easier on car finishes than brushers, especially on newer finished (more easily scratched)

A. On the road? Whoa that is a leap! There can be plenty of cars on the road that have never been to a car wash, let alone a modern one
B. We don't know why the brushless car washers were introduced
C. I'm suspicious about the usually but let's keep for now
D. We don't know anything about which is preferred and the more effective is a bit strong for me
E. We don't know about the cars in use today. This is trying to get you to assume more cars in use are newer cars

[Laura Damone]

Nailed it! C is definitely not an attractive answer for two reasons: the degree of "usually" and the specificity of "visible scratches." And yet, the other answers are clearly worse for the reasons you cited, so C is the best answer around. Nice work!