Logical reasoning PrepTest 147 · Section 4 · Question 12

Incorrect. As we noted, Young's rebuttal doesn't address a common error in reasoning made by West—he brings up a new fact that calls her assumption into question.

Incorrect. Young might imply West's conclusion is wrong with an additional fact, but that's not calling its relevance into question. This answer would be correct if the rebuttal boiled down to, "So what? X is what's really important."

Incorrect. West's premises are that there are 3 inspectors, and Haynes accounts for 50% of returns. Young doesn't question either of those, instead bringing up a separate fact that provides context calling the conclusion into question.

Incorrect. First, Young's statement implies that Haynes is better than at least one other inspector. Second, Young doesn't really have a conclusion—we don't know if he believes Haynes is the best or just not the worst inspector.

Correct. Argument or Facts:
Argument/Facts

Valid or Flawed:
Flawed/NA

Question Type:
Methods of Reasoning

Stimulus Summary:
W: Half of our returns for defects were inspected by Haynes, so he's the worst of our three inspectors.

Y: Haynes inspects much more than half of our appliances.

Answer Anticipation:
For these Methods of Reasoning questions that ask about a rebuttal, it can be a good idea to start by seeing if the response addresses the premise, the conclusion, or both.

Here, Young's response doesn't address the premise. He seems to accept West's number—that half of the defective returned products were inspected by Haynes. However, he does disagree with the conclusion that Haynes is the worst inspector based on a separate consideration.

Does that separate consideration address the logic of the argument, or an assumption? Young doesn't point out a common error in reasoning in the argument, so it must be that Young's statement addresses an assumption.

West assumes that 50% of the returns having been inspected by Haynes is a disproportionately large share given there are three inspectors—all things equal, each should have ~33% of the returns. In bringing up the higher rate of inspections done by Haynes, Young calls that assumption into question.

Answer Explanation:
West assumes that 50% is a disproportionately large share of defects to get through an inspector. Young, in bringing up that Haynes inspects more than 50% of the appliances, suggests that it isn't a disproportionately large share.

Key Takeaway:
When dealing with a rebuttal-based Methods of Reasoning question, start by identifying if the second speaker addresses a premise or the conclusion. If the latter, move on to see if the second speaker points out an error in reasoning, or introduces evidence to call an assumption into question. This won't cover 100% of cases, but it'll give you a good start even if it doesn't.