Logical reasoning PrepTest 103 · Section 1 · Question 12

Question prompt

On their way from Remaining source text redacted.
Why the credited answer is right

Credited answer: C

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

Argument or Facts

Facts

Valid or Flawed

NA

Question Type

Must Be True Questions

Stimulus Summary

Most ants leave pheromones between the nest and food sources, using them to find their way Pheromones evaporate without a trace above 45C The Sahara gets above that temperature in the afternoon

Answer Anticipation

Must be True questions are generally about identifying overlap between statements that let you build to an inference. Here, we get three individual statements that do build together, even though they’re not all purely conditional. Here, we learn that pheromones are used by most ant species to guide the way between the nest and food sources. However, these pheromones evaporate “without a trace almost immediately” in 45+C heat. This means that those pheromones will not help ants find food at that temperature. And it gets that hot in the afternoon of the Sahara. Putting these statements together, we can infer that ants that try to get food in the Sahara in the afternoon can’t be relying on pheromones to find their way, so let’s see if there is an answer reflecting that.

Answer choices

  1. A
    Most ants forage for Remaining source text redacted.
    Why choice A is not credited
    This answer assumes that most ants live in areas that get above 45C in the afternoon, but there’s no indication that this is the case, so this answer is unsupported.
  2. B
    Most ants that do Remaining source text redacted.
    Why choice B is not credited
    There’s no indication that any ants live in the Sahara, let alone that most that don’t use pheromones live there.
  3. C
    If any ants live Remaining source text redacted.
    Why choice C matches the stem
    The Saharan afternoon is hot enough that pheromones evaporate almost immediately, leaving no trace. If an ant is foraging at that time, then, they wouldn’t be able to use pheromones to guide themselves, so this answer is supported.
  4. D
    If any ants do Remaining source text redacted.
    Why choice D is not credited
    There’s no discussion of alternatives to pheromones - it could be a different substance, or it could be something like directional sense!
  5. E
    If any Saharan ants Remaining source text redacted.
    Why choice E is not credited
    We don’t know that these ants use pheromones to navigate their way to forage sites, so we can’t say that they’re less effective at times when temperatures cause pheromones not to work.

What this tests

Question analytics

Based on historical answer selection rates for this question.

Answer choice distribution

  1. A 12%
  2. B 1%
  3. C Credited 59%
  4. D 1%
  5. E 26%

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