Q10 - Cafeteria patron: The apples sold

[wayne_palmer10]

This is a necessary assumption question. I selected (B) but don't undertand why (A) is correct. Is (B) wrong because it's too general (i.e. it doesn;t talk about the cafeteria's apples)?

[dan]

What happens if we negate answer choice (A) (take the opposite)?

The apples that the cafeteria sells ARE thoroughly washed after harvest but before reaching the cafeteria.

This would destroy the argument that the apples are dangerous (if they are washed, then they are no longer dangerous). So, negating the assumption destroys the argument. This means that the assumption, in it's original form, is required for the conclusion to be drawn.

Another way to look at this:

Most fruit sprayed with pesticides before harvest --->
Dangerous until washed --->
Cafeteria does not wash apples --->
Apples dangerous

There are a few assumptions that are required here: (1) that the apples were actually sprayed (just because "most" fruit is sprayed doesn't mean the apples were sprayed, and just because they are greasy doesn't mean they were sprayed!), and (2) that the apples weren't washed before arriving at the cafeteria (maybe they were washed before they were shipped).

Both of these are required assumptions, but the correct answer need not express both. Answer (A) expresses the second of these.

Answer (B) is a very attractive answer that links the pesticides with grease, but it's wrong. We DO need to assume that the apples were sprayed with pesticides in order to conclude that the apples are dangerous (the first assumption from above), but saying that most pesticides lead to a greasy residue does NOT guarantee that the apples were sprayed! Take the following example:

Athletes are muscular. Lifting weights leads to muscularity. Thus, athletes lift weights.

Not necessarily true! this is reversed logic (weights ---> muscularity, SO muscularity --->weights). Maybe the athletes are muscular for another reason... the practice their sports a lot, for example.

Similarly:

Apples are greasy. Pesticides lead to grease. Thus, apples have been sprayed by pesticides.

Not necessarily true! This is reversed logic as well (pesticides ---> grease, SO grease ---> pesticides).

It feels like (B) gives us a guarantee that the apples have been sprayed, but it actually doesn't. Maybe the apples are greasy because they've been handled by lots of people in the process of shipping.

Make sense?

dan

[magnumlifestyle]

dan,

first of all, thanks for your answer.
But I still had a question.

Negating the answer choice (A) certainly seems to make sense.

But when you don't negate it (meaning, as it is), the answer choice states that apples aren't washed after the harvest but they are washed before reaching the cafeteria.

If they are washed before reaching the cafeteria, as answer choice A states, then the apples cannot be endangering to patrons.

How can this possibly be an assumption?

I understand that you recommend negating answer choices to solve assumption questions, but when answer choice A isn't negated, it completely destroys the argument.

I would really appreciate your further thoughts on this matter.

[dan]

Thanks for the follow-up question. I think you might be getting turned around (really easy to do on the LSAT!).

The conclusion is that the apples are dangerous. Answer choice (A) states that the apples are NOT washed before reaching the cafeteria. This assumption supports the argument that the apples are dangerous.

Negating the assumption, or saying that the apples ARE washed before reaching the cafeteria, would mean that the apples are NOT dangerous. This destroys the argument.

So, the assumption in (A) as stated supports the argument and the negation of the assumption in (A) destroys the argument.

Let me know if that makes sense, and best of luck with the rest of your LSAT studying.

dan

[magnumlifestyle]

Thanks Dan.

Your explanation is very clear, crisp and coherent.

What's interesting is that you, by default, understood the sentence, "The apples that the cafeteria sells are not thoroughly washed after harvest but before reaching the cafeteria" to mean that "the apples are NOT washed before reaching the cafeteria."

The issue I raised in my follow up question pertains to the use of the conjunction "but."

I understood the answer choice to mean that the apples are NOT washed AFTER harvest but they are WASHED before reaching the cafeteria.


I thought that the testmakers had deliberately chosen to use the word "but" instead of "and" in order to establish that the apples were washed BEFORE reaching the cafeteria.

But I think I misinterpreted the word.

I'm curious though....

When you first read this answer choice, did you automatically understand that the answer choice was saying that the apples were NOT washed AFTER harvest and BEFORE reaching the cafeteria?

I know I sound like a gunner (obsessing over a single word) but I ask this because I've had similar problems before where I misinterpreted the WHOLE sentence due to ONE single word.

Anyways, thanks Dan for following up on my question.

[dan]

Ah. I see exactly what you mean. One thing to keep in mind is that the LSAT is subtle, but it's never intended to be ambiguous. In other words, the test writers do not deliberately write sentences or phrases that are designed to be interpreted in more than one way. It's great that you're looking for subtlety in detail, but in this case I think you've simply misinterpreted the meaning of the sentence.

Take this example:

I went to the store after Monday but before Friday.

How would you interpret this sentence? List out the possible days on which I went to the store. Take a second and think about it before reading on.

"After Monday but before Friday" means sometime between Monday and Friday. So the possible days on which I went to the store are Tuesday, Wednesday, and Thursday. The idiom "After X but before Y" serves to set up a time frame that is bounded on the front end by X and on the back end by Y.

If we make it negative:

I did NOT go to the store after Monday but before Friday.

...we interpret it the same way. I did NOT go on Tuesday, Wednesday, or Thursday.

In the case of the apples:

The apples were not washed after harvest but before reaching the cafeteria.

We have a bounded timeframe with harvest being the front end and reaching the cafeteria being the back end. The apples were not washed in that timeframe.

Hope that helps.

dan

[magnumlifestyle]

dan,

You couldn't have said it better.
I never knew that such idioms ("After X but before Y") existed.
Now everything makes perfect sense -- can't believe I missed this problem!

I hope future users benefit from your explanation (so much better than Kaplan's explanation).

thanks dan!

[gotomedschool]

That was the best explanation I have read on these message boards since being a registered user.


Like the OP, I too was confused by the usage of "but" as a conjunction and implied it to mean not thorughly washed after harvest BUT washed before reaching the cafeteria. Had they used and or used or, it would have been crystal clear to me.

Not thorughly washed after harvest or before reaching the cafeteria--> bang! totally get it.

Not thoroughly washed after harvest and not before reaching the cafeteria--> BANG! also totally get it

BUT

Not thoroughly washed after harvest but before reaching the cafeteria---> EH? Does this mean they are washed before reaching the cafeteria?!?!


I totally did not understand this until you explained it. I feel like this is a flashback to 9th grade English class. If you just eliminate the prepositional phrase "after harvest" then it reads as not thoruhlgy washed before reaching the cafeteria which is what it's trying to get at.

[WaltGrace1983]

Would (B) be correct if it said that "Some pesticides that are sprayed on fruit before harvest leave a greasy residue?"

It seems that the argument uses the "apples being greasy" as evidence that the pesticide was sprayed on it. If we say that "NO pesticide makes apples greasy" (the negation of this modified (B) answer choice) and we know that "the apples are greasy" then this would destroy the argument that the apples are "sprayed with pesticide."

What do you think?

Thanks guys and girls!

[maryadkins]

No because the argument doesn't hinge on them being greasy. The argument is more reliant on "Most fruit is sprayed..." and the cafeteria not washing the fruit. Even if it's greasy for a different reason, like...I don't know...that doesn't make the argument fall apart because there's still a case to be made:

Most fruit sprayed and is dangerous until washed

+ Cafeteria doesn't wash

-->

Dangerous fruit at cafeteria

I think greasy is just background/superfluous support.

[stm_512]

I clearly understand why A is correct, but what is the proper negation of C?

Is it,
i) Many of the cafeteria's patrons are aware that the cafeteria does not wash the apples it sells. or
ii) None of the cafeteria's patrons are unaware that the cafeteria does not wash the apples it sells.

If the proper negation is i, it does not destroy the argument because it does not preclude the possibility that some others are unaware.

But if the proper negation is ii, then every cafeteria patron is aware of of the danger, clearly undermining the argument!

[WaltGrace1983]

Your thinking is a bit backwards on this, I believe. Neither (i) nor (ii), when negated, would actually do anything to the argument. Why? Because awareness has nothing to do with the gap between the premise and the conclusion.

Most fruit is sprayed with dangerous pesticides before it is harvested
+
If covered in pesticide, dangerous until washed
+
Cafeteria doesn't wash apples it sells
→
Cafeteria is selling pesticide covered fruit, endangering its patrons

There are a few gaps to attack here. Here is a list of possibilities:

(1) The apples that the cafeteria sells are actually a part of the "most fruit sprayed with dangerous pesticides" group. If they are not, then why would they be dangerous or covered in pesticide?
(2) That there is no washing that happens after being covered in pesticide and before being given to cafeteria because, as we know, the cafeteria certainly doesn't wash them!
(3) That pesticides are indeed dangerous. This one really isn't a gap to attack though because we are probably going to accept this as a premise rather than an intermediate conclusion (let me know if you don't know what I mean.

This list is certainly not exhaustive and there may be more necessary assumptions but the best answers are usually ones that are most explicit (though definitely not always the most obvious!).

The negation of (C) is "NOT many of the cafeteria's are unaware that the cafeteria does not wash the applies it sells." Now the real question is, does "NOT many" = "none?" I ask this because some believe that "many" and "some" are interchangeable and the negation of "some" is "none." However, we can be sure that the negation is "NOT many," regardless of the implications of this. To understand why this is, read the Manhattan LR guide or perhaps other stuff online. Anyone could explain it better than I could I bet!

i) Many of the cafeteria's patrons are aware that the cafeteria does not wash the apples it sells. or
ii) None of the cafeteria's patrons are unaware that the cafeteria does not wash the apples it sells.

But if the proper negation is ii, then every cafeteria patron is aware of of the danger, clearly undermining the argument!

Nope! Awareness never does anything to the argument. They are aware; they aren't aware. Who cares?! This is because the argument can stand either way! Think about it. If you took the idea that "everyone in the cafeteria is aware" and placed it in the middle of the argument, what happens?

Most fruit is sprayed with dangerous pesticides before it is harvested
+
If covered in pesticide, dangerous until washed
+
Cafeteria doesn't wash apples it sells
+
Cafeteria workers are aware!
→
Cafeteria is selling pesticide covered fruit, endangering its patrons

The answer is nothing. This means that it cannot be the correct answer; the argument stands perfectly fine with and without the assumption!

What do you think, stm_512?

[stm_512]

Looking back at this question and reading WaltGrace's response, it makes more sense now.

Just because the patrons are aware of the dangers, we can't add an additional layer of assumption that they will do something about it.

With regards to A), I completely misunderstood the meaning of the sentence.

If the sentence read: the apples that the cafeteria sells are not: thoroughly washed after harvest but before teaching the cafeteria, then it's extremely clear.

But I read A) as: the apples that the cafeteria sells are not thoroughly washed after harvest, but they are washed before reaching the cafeteria.

I still don't understand why my version of understanding of this sentence is wrong.

Edit: I just realized my version of understanding leads to a timing contradiction.