Logical reasoning PrepTest 106 · Section 3 · Question 16

Question prompt

Historian: We can learn Remaining source text redacted.
Why the credited answer is right

Credited answer: B

The notes below walk through why it fits the stem and how to eliminate the rest.

Argument or Facts

Argument

Valid or Flawed

Flawed

Question Type

Strengthen with Necessary Premise Questions

Stimulus Summary

(A whole bunch of history). Mercury treated VD, so if researchers find mercury in Beethoven’s hair, his VD caused deafness.

Answer Anticipation

There is a lot of information in this stimulus, so it’s important to use the conclusion to narrow down the relevant information.
The conclusion here is clearly stated in the last clause (“we can conclude”), and it claims that a hypothesis is correct if mercury is found in Beethoven’s hair. Well, that means we should find what the hypothesis is and rephrase this conclusion to reflect it. The hypothesis is stated a few lines before, saying that Beethoven’s deafness was caused by VD. So the conclusion is that, if mercury is found in his hair, Beethoven’s deafness was caused by VD.
Why does the Historian believe this is true? Because mercury was commonly ingested to treat VD. That’s it. There’s a whole lot of other information, but the premise supporting the conclusion is just that! Limiting the argument like this is going to be very helpful in not getting distracted here.
So what’s wrong with the argument? Well, mercury was ingested to treat VD, but that doesn’t mean that everyone with mercury in their hair had VD. Maybe mercury was used to treat other things at the time, or maybe it was consumed for non-medicinal reasons (e.g., people thought it was good for digestion). The argument assumes that mercury would be present only if used to treat VD, so let’s find an answer stating that, or ruling out a reason to ingest it for other reasons.

Answer choices

  1. A
    None of the mercury Remaining source text redacted.
    Why choice A is not credited
    First, the argument requires only that some mercury remains once ingested, not that all of it remains. Second, even ignoring that, the argument’s conclusion is based on mercury being found - it doesn’t say that if mercury isn’t found, then VD isn’t responsible for Beethoven’s deafness!
  2. B
    Some people in Beethoven's Remaining source text redacted.
    Why choice B matches the stem
    While this answer doesn’t speak to reasons for mercury ingestion, it does set a baseline for the argument. If everyone in Beethoven’s time ingested mercury, then mercury in Beethoven’s hair doesn’t suggest he was taking it to treat VD - people who didn’t have VD would also have mercury in their system! That kills the argument that mercury is an indicator of VD, so this is a necessary premise.
  3. C
    Mercury is an effective Remaining source text redacted.
    Why choice C is not credited
    For the argument to work, people in Beethoven’s time needed to take mercury for VD, but it didn’t have to actually work to cure it! Even if it was ineffective, it could still indicate VD treatment.
  4. D
    Mercury poisoning can cause Remaining source text redacted.
    Why choice D is not credited
    If anything, this hurts the argument that VD caused Beethoven’s deafness in proposing that it was the mercury that caused the deafness. Even if we view the VD as being the cause of deafness when mercury used to treat it causes it, that’s not necessary for the argument to work - the VD could directly cause deafness.
  5. E
    Beethoven suffered from psychological Remaining source text redacted.
    Why choice E is not credited
    There’s no need for Beethoven to have psychological problems for the argument to work, as those are noted as separate from the VD. Newton’s psychological problems could have been the result of taking mercury at a level much higher than Beethoven!

What this tests

Question analytics

Based on historical answer selection rates for this question.

Answer choice distribution

  1. A 25%
  2. B Credited 37%
  3. C 9%
  4. D 25%
  5. E 3%

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Discussion

  • Answer B 1 reply

    Started by RitaW

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