Logical reasoning PrepTest 106 · Section 1 · Question 5

Question prompt

The number of codfish Remaining source text redacted.
Why the credited answer is right

Credited answer: D

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

Cause & Effect / Weaken Questions

Stimulus Summary

Phenomenon - The codfish population has decreased as the seal population has increased
Explanation - The increase in the seal population caused the decrease in the cod population
Problem with explanation - Seals don’t really eat cod
Conclusion - The seals don’t explain the cod

Answer Anticipation

Interesting Weaken question! Normally, we’d see a correlation (cod population down; seal population up) lead to a causal conclusion. Here, however, the argument says that drawing such a causal conclusion is incorrect - it’s unlikely that the increase in the seal population caused the decline in the cod population.
When an argument says that a causal relationship doesn’t exist, anything suggesting that it might exist will weaken it. So here, any answer that says the seal population increasing may actually be contributing to the decline of the cod population would weaken the argument. While the seals aren’t eating the cod, let’s find an answer saying that they’re causing the decline through some other mechanism.

Answer choices

  1. A
    People who fish for Remaining source text redacted.
    Why choice A is not credited
    If anything, this would suggest that the seal population would increase the cod population by making it more inconvenient for the fisherman to fish for cod.
  2. B
    Water pollution poses a Remaining source text redacted.
    Why choice B is not credited
    Stating that one thing is a more serious threat doesn’t mean that something else can’t be a serious threat.
  3. C
    The harp seal thrives Remaining source text redacted.
    Why choice C is not credited
    This answer seems to suggest that it’s the water temperature that contributed to the decline in cod population, which aligns with the argument that it wasn’t the seal population.
  4. D
    Cod feed almost exclusively Remaining source text redacted.
    Why choice D matches the stem
    This answer suggests an indirect way that an increase in the seal population could lead to a decrease in the cod population, weakening the conclusion. If the more numerous seals are eating more and more of the cod’s food source, then there would be less food for the cod, leading to a population decrease.
  5. E
    The cod population in Remaining source text redacted.
    Why choice E is not credited
    If the supposed effect started before the supposed cause, that weakens the argument for causality. And since the conclusion here is that there isn’t a causal relationship, this answer aligns with that conclusion.

What this tests

Question analytics

Based on historical answer selection rates for this question.

Answer choice distribution

  1. A 9%
  2. B 0%
  3. C 2%
  4. D Credited 83%
  5. E 6%

Deeper help

Ask follow-ups on any step

Optional AI tutor mode will let you interrogate assumptions, compare answers, and drill weak patterns without leaving the page.

Human-written explanations stay primary; AI is an add-on when you want it.

Discussion

View all discussions Start a discussion