Logical reasoning PrepTest 131 · Section 2 · Question 19

Incorrect. This answer is an illegal reversal of a conditional from the stimulus.

Incorrect. Very close! However, this answer is the negation of the inference we made.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Bankers → Athletes
Lawyers → not Bankers

Answer Anticipation:
This question sent people into a tailspin on the LSAT! People believed that there were no valid inferences to be made, and we can see why.

Normally, conditional statements have a shared term that's present in the sufficient condition of one statement and the necessary condition of another, allowing a chain to be built. Here, the shared term is "Bankers" and, to get them to have the same negation state, we need to take the contrapositive (we're taking a contrapositive of the second just to keep the shared term positive):

Bankers → Athletes
Bankers → not Lawyers

Looking at that and trying to form an inference can be maddening, as it seems as if the LSAT has made a mistake!

But they haven't—instead, they've created a devious question. We can make an inference here, but we have to use a different set of rules—our quantifier rules. Yes, there are no mosts or somes, but the argument is talking about various groups, so we can use our quantifier rules to see if there's any overlap.

The shared group in question is Bankers. And we know that Bankers are both Athletes and not Lawyers. Since there are some people out there (Bankers) who are both Athletes and not Lawyers, we know that some people who are Athletes are not Lawyers:

Athletes-some-not Lawyers

This follows our quantifier rules, as the first statement talks about 100% of bankers at this gathering, and the second also talks about 100% of bankers. Those two groups, therefore, must overlap to lead to that inference—just as it would if the first statement were a most or a some statement.

Answer Explanation:
This answer reflects that bankers are both athletes and not lawyers, so there are some people at the party (bankers) who are athletes but not lawyers.

Key Takeaway:
The rule allowing this inference to be made is something you either know or you don't, so there's not much of a takeaway here: If two conditionals share a sufficient condition, then a some inference can be made connecting their necessary conditions.

The bigger takeaway has to do with test strategy—this is a great example of a question that could cause you to spin your wheels and stare at it for 2 . . . 3 . . . 4 minutes before picking an answer and moving on. You simply don't have the time for that, so start to develop a sense for when you're stalled and feel free to make your best guess and move on.

Incorrect. This answer is directly contradicted by the stimulus, where we're told none of the lawyers are bankers.

Incorrect. Bankers are athletes but not lawyers, but some of the lawyers could be athletes—there's nothing in the stimulus preventing that.