Logical reasoning PrepTest 139 · Section 4 · Question 11

Incorrect. The argument concludes that the process isn't very difficult, so this answer about necessary/sufficient conditions for difficulty is a negation of the logic in the stimulus.

Incorrect. The conclusion's scope is limited to whether the certification is difficult, not whether they're qualified. In fact, the argument is about whether a group is more qualified, not qualified.

Incorrect. While the stimulus does discuss relative qualification, the conclusion is about whether the certification process is difficult—not more difficult than other certification processes. This shift away from the comparisons in the first half of the stimulus which turned out to be background means that a relative answer such as this one is incorrect. (You can tell there was a shift from the relative qualification discussion when the author says the plumbers "may or may not" be more qualified.)

Incorrect. Plumb-Ace does claim that their certification process is "very difficult," which the argument concludes is false. However, it doesn't do so based on a flaw in Plumb-Ace's argument, but rather because of the high rate of passing a portion of the certification process.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Errors in Reasoning

Stimulus Summary:
Plumb-Ace: Our plumbers go through a very difficult certification process, so they're more qualified than competitors.

Author: Forget the relative qualification for a second. Almost everyone passes the written portion of your certification, so it must not be that hard.

Answer Anticipation:
There's a key word here that should set us up to think towards the right error in reasoning—"portion." Whenever an argument is discussing a piece of something, there's a chance that it's jumping from what is true of the part to what is true of the whole.

Here, the conclusion is about a whole—the certification process overall. It concludes that it's easy because one piece of it—the written portion—has a very high pass rate. That's assuming the qualities of this portion also applies to the entire certification, so there's a part to whole jump here that should be reflected in the correct answer.

Answer Explanation:
This argument jumps from the write portion of the certification being easy to the entire certification being easy. It's possible that the written portion is meant to weed out people who have no business being plumbers, and then the rest of the certification process is actually quite difficult to determine the best candidates for a Plumb-Ace job.

Key Takeaway:
Whenever an Errors in Reasoning question features language that talks about an individual, part, portion, or element, see if it uses the premise about that part to draw a conclusion about the whole that it's a part of. That's a flawed jump.