Cafeteria patron: The apples sold

Answer choices

1. A

   Correct59% picked this

   The apples that the cafeteria sells are not thoroughly washed after harvest but before

   Why this is right

   Whenever we're doing Necessary Assumption, and we see an answer choice that is ruling out an idea with the word "not", we should be very receptive (tons of correct answers take that form, because they're ruling out an objection). "Not" claims are easy to negate. If we negate this one, does it turn into an objection: the apples are thoroughly washed after harvest but before reaching the cafeteria. Yes, that would be a huge objection. The author is concluding that these apples are covered in pesticides, but if the apples have already been thoroughly washed then they his conclusion is wrong; they aren't covered in pesticides.

   Skill tested: Necessary Assumption · how this choice captures the argument's function is the move to repeat next time.

   59%
2. B

   Too Strong: most31% picked this

   Most pesticides that are sprayed on fruit before harvest leave a greasy residue

   The author doesn't need to assume that the grease and the pesticides are causally connected. He is only looking at the grease as an indicator that the apples haven't been washed. Furthermore, the word "most" is wrong 99% of the time we see it in Necessary Assumption. Negating a "most" claim means you take the claim from saying "at least 51%" to "at most 49%". Would it hurt this argument to say, "at most 49% of pesticides leave a greasy residue"? No. If the negation doesn't weaken, it wasn't a required idea.

   31%
3. C

   Out of Scope: patrons' awareness4% picked this

   Many of the cafeteria’s patrons are unaware that the cafeteria does not wash the

   The awareness of patrons is completely out of scope. We're only trying to assess whether these apples are / aren't covered in pesticides. That could be true whether people are aware of it or oblivious to it.

   4%
4. D

   Too Strong: only Unsupported Relationship2% picked this

   Only pesticides that leave a greasy residue on fruit can be

   This has strong wording to make us nervous: only. Since that's conditional strength, we can analyze this answer by thinking of the conditional rule it describes and asking ourselves, "Did the author clearly make this move in his logic?" "Only" = necessary (right side) indicator. Pesticide can be ? leaves a greasy washed off residue No, the author definitely didn't establish in the premise that "this pesticide can be washed off" and then conclude "therefore, this will leave a greasy residue". Does this negation hurt the argument? "at least one pesticide that doesn't leave a greasy residue can be washed off" Not at all. The author was never thinking that a pesticide couldn't be washed off, just that it hadn't been washed off.

   2%
5. E

   Out of Scope: other than apples4% picked this

   Fruits other than apples also arrive at the cafeteria in a

   We've only heard that apples are greasy. The author doesn't need to assume that anything else was greasy. His argument is about pesticides, not grease. (Although he doesn't even need to assume that any other fruit has pesticides, either)

   4%