Logical reasoning PrepTest 114 · Section 2 · Question 18

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Parallel Reasoning

Stimulus Summary:
not Measure → not Science
not Select units → not Measure
Selecting units is arbitrary
Therefore — Science is arbitrary

Answer Anticipation:
The argument here presents two conditionals ("without"). We diagrammed these treating "without" as "if not" (it's equivalent to "unless" "until" and "except" when used in a conditional) but if you diagrammed them with another method that's fine—you probably ended up with the contrapositives.

These two conditionals chain together to show us that science requires selecting units (Science → Measure → Select units). It then establishes that the necessary condition here is arbitrary and concludes that the sufficient condition is also arbitrary.

So to generalize a form we can look for:
A → B
B → C
C is X
Therefore — A is X

Answer Explanation:
This argument has two conditionals and then assigns a trait to one of them so we should diagram it out:
Musical skill → Lots of practice
Perform difficult music → Musical skill
Practice is tedious so performing difficult music is tedious.
This argument has two conditionals that chain together and it then establishes the necessary condition has a trait so the sufficient must similarly have that trait. This answer is therefore correct.

Key Takeaway:
Parallel Reasoning questions have a very high bar for a correct answer. By identifying a few key features up front you can make some quick eliminations for answers that have elements not present in the stimulus or for lacking a key logical element found there.

Incorrect. This answer features one conditional premise and a premise that assigns a trait to something. It's missing a second conditional premise.

Incorrect. The third premise here doesn't assign a characteristic to a condition in the conditionals. Rather it brings up one possible way to achieve it. Since this answer has a premise that features different logic than the stimulus it's incorrect.

Incorrect. This answer features two conditional premises and a premise assigning a trait to one ("because . . . ") so we should diagram it out: not Evaluate people → not Be a manager Evaluate people → Subjective People resent being subjectively evaluated . . . and this is where it gets thrown off. The stimulus assigned a trait to the condition—there is said that selecting a unit of measurement is arbitrary. Here the condition is engaging in subjective evaluation whereas the trait is assigned to being subjectively evaluated—a subtle shift but enough to throw this answer off.

Incorrect. The "Some" makes this answer suspect right off the bat and the second statement talking about "[t]his irrigation" instead of irrigation generally is also off. The stimulus establishes general conditionals whereas this answer is speaking to only some/specific instances so the logical scope is different.