Logical reasoning PrepTest 145 · Section 4 · Question 13

Incorrect. The group that is only skilled at playing the guitar can dwarf the group that's skilled at playing both.

Incorrect. The likelihood of success is out of scope of this argument. Just because there are more people skilled at playing the guitar than the banjo doesn't mean that it's more likely to get good at that instrument—it could also be a factor of how many people pick it up in the first place.

Incorrect. There's no discussion of how much skill it takes to play the given instruments.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Skilled banjo player-most-Skilled guitar player
Skilled guitar player-most-not Skilled banjo player

Answer Anticipation:
At first blanch, this question very much seems like an overlapping sets/quantifier question. After all, there are a couple most statements to contend with.

However, after diagramming them out, it should quickly become apparent that they can't be combined as we normally do with quantified statements. Two most statements need to share that first term to lead to an inference, which doesn't happen here. And that's good—we don't want an inference stating that some skilled banjo players aren't skilled banjo players!

So what is the correct answer going to state? Since we get information about overlap between skilled banjo players and skilled guitar players, this answer is likely going to deal with the relative sizes of some of these groups. While we normally can't use quantified statements to determine these comparative sizes, when the statements overlap as these do, there's a chance we can. And since they both discuss skilled guitar players—we know more about them than any other group—they're likely to be featured in the correct answer.

Is there an anticipation we can form before we head into the answers about that group? We should think about if we can determine the relative size of that group compared to skilled banjo players. We do know that everyone is either skilled at playing the banjo, or they're not skilled at playing the banjo (same for guitar). We know that the people skilled at both—which would be the point of comparison for both groups—make up a majority of those skilled at banjo (the implication of the first sentence) but a minority of those skilled at guitar (the implication of the second sentence). If the shared members of the two groups make up a larger proportion of the skilled banjo group than the skilled guitar group, then the skilled guitar group must be larger! Let's find that answer.

Answer Explanation:
This answer is justified by the stimulus. The shared group—those who are skilled at both instruments—makes up a larger proportion of the skilled banjo group than the skilled guitar group, so the former group must be smaller than the latter.

Key Takeaway:
This is a rare quantifier-based question that doesn't ask you to combine the statements using our quantifier rules. When that happens, see if you can identify a shared group between the statements as a point of comparison to see their relative sizes.

Incorrect. This answer is contradicted by the stimulus (and anyone's experiences with reality!).