Logical reasoning PrepTest 120 · Section 4 · Question 17

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Flawed Parallel Reasoning

Stimulus Summary:
not Been asked to do more than is easy → not Do all they can
Alex: not Do all they can
Therefore - Alex: not Been asked to do more than is easy

Answer Anticipation:
This argument starts with a statement of what is true of all people who fit a certain criteria—while it doesn't use a particular conditional indicator word, the certainty allows us to diagram it out. (Short version, the unmodified "People" implies that it's about all people in the group, and the definitive "are" tells us that there's no wiggle room—it's a certainty that they have a certain trait.)

With that noted, we can see that Alex meets the necessary condition of the conditional, and that is used to justify a conclusion that he meets the sufficient condition. That's an illegal reversal, so we should head into the answer choices looking for an argument that commits the same flaw.

Answer Explanation:
Has dog → Knows true value of companionship
Alicia: Knows true value of companionship
Therefore - Alicia: Has dog
This argument has the exact same illegal reversal as the stimulus, so it's the correct answer.

Key Takeaway:
An unmodified group is implied to be about all of that group (e.g., people, students, Americans, etc . . . ). And definitive/certain verbs—is, are, will—can be diagrammed conditionally.

Incorrect. Fran doesn't meet the sufficient condition of the opening line, so this answer features an illegal negation, not an illegal reversal.

Incorrect. not Face sufficient challenge → not Accomplish everything they can
Jill: Accomplish everything she can
Therefore - Jill: Face sufficient challenge
This argument is a valid application of the contrapositive, so it's not even flawed!

Incorrect. Without even diagramming this answer, we should be able to determine that this is a valid argument that just applies a conditional/definition to a specific case that meets it.

Incorrect. Without diagramming this out, we can see that what we learn about Jon conflates the two conditions in the opening line, mixing and matching pieces of both, so it's committing a different flaw.