Logical Reasoning

PT129 · S1 · Q21 Several people came down with an illness

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Several people came down with an illness caused by a type of bacteria in seafood.

Paradox

Health officials believe that all the people who got food poisoning from a bacteria in seafood got it from the same restaurant on the same date, via contaminated seafood. YET Most people who ate seafood at that restaurant on that date did not come into contact with this bacteria.

Evaluation

There could be lots of ways to resolve this paradox, but it seems like a pretty easy one to offer a solution for. If there was only one contaminated flank of salmon at the restaurant that day, then all the people who ate it would have gotten the illness, whereas most of the people who ate seafood at the restaurant that day would not have come into contact with the bacteria, since they weren’t served any of that one contaminated piece of fish. Somehow, the answer will probably make use of the fact that seafood is a broad category, so the people who got sick may have all eaten the same type of seafood or even same specimen of animal, whereas the people who didn’t get exposed to the bacteria probably just ate a different type of seafood or a different specimen of the contaminated type.

Goal

How can it be simultaneously true that all the sick people got it from bacteria-contaminated seafood at this restaurant on a given day, while most people who ate seafood there that day did not get exposed to the bacteria?

21.

Which one of the following, if true, most helps to resolve the apparent discrepancy indicated above?

  1. Most people are immune to

    Out of Scope: "immune"

    Being immune to the bacteria is not the same as not coming into contact with it, so this couldn’t help us to explain that part of the mystery. If the paradox had been, “Given that most people came into contact with it, how come only several got the illness”, then this answer would work.

    5% picked this

  2. Those made ill by the

    Unclear Impact / Irrelevant Distinction

    We have no idea if the waiter also ate this seafood or even if the subsequent illness was the same as that suffered by the patrons. This also doesn’t help us explain why the majority of seafood eaters weren’t exposed to the bacteria.

    18% picked this

  3. All and only those who

    Opposite /Irrelevant: "allergic to MSG"

    We were told that the sickness came from bacteria, not an allergy to MSG. So either this is saying, “the sick people ALSO had an allergic reaction” or it’s trying to contradict the given idea that the sickness came from ingesting a bacteria, not MSG.

    11% picked this

  4. The restaurant in question had

    Explains Background, Not Surprise

    This adds some context to why the restaurant might serve contaminated seafood, but it doesn’t help us explain why the majority of seafood eaters didn’t get exposed to the bacteria.

    3% picked this

  5. Correct

    All and only those who

    Why this is right

    This gets at the overly broad category of ‘seafood’ from the paradox. Most seafood eaters didn’t get the bacteria, but maybe all the people who ordered scallops got the bacteria. The keyword that distinguishes the sick group from the rest of the seafood eaters is a particular seafood dish. The bacteria could have been only found in the Scallops Au Gratin, and everyone who ate that got sick. Everyone who didn’t eat that dish, didn’t get sick (whether they ordered seafood or not).

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

    64% picked this

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