PrepTest 115

Incorrect. Skilled artist-most-Good at abstract reasoning. This answer is the inference that the first two premises already allow to be drawn, so it doesn't add anything to the argument.

Incorrect. Very creative-most-Skilled artist. This answer reverses the first premise. While that could be correct if the argument was flawed in that it needed the premise to be reversed, we already showed in our anticipation that statement #1 can build to the conclusion with another premise added in, so this reversal doesn't lead to the conclusion.

Incorrect. The conclusion is about people who are famous, so this answer about people who aren't is out of scope. Remember—you can't infer from a statement that some people aren't something that others are.

Incorrect. Good at abstract reasoning → Very creative. This answer is similar to (B) in that it reverses a premise we already showed could lead to the conclusion with a stronger version of the third statement added in. As such, there's no reversal in the argument and thus this answer doesn't lead to the conclusion.

Correct. Argument or Facts:
Argument

Valid or Flawed:
Flawed

Question Type:
Strengthen with Sufficient Premise

Stimulus Summary:
(1) Skilled artist-most-Very creative
(2) Very creative → Good at abstract reasoning
(3) Skilled artist-some-Famous
Therefore - Good at abstract reasoning-some-Famous

Answer Anticipation:
This is a devilish quantifier Strengthen with Sufficient Premise question, so let's talk about how best to tackle it.

First, be sure you know your quantifier rules! Without them, this question is going to be nearly impossible.

That said, let's look at what we're given, and what we can infer based on it. Normally, the premises will lead to some inferences that'll fall short of establishing the conclusion, and then the correct answer comes in and fixes that shortcoming.

Here, the only two statements that can be combined to get an inference are #1 and #2. Using our quantifier rules, we can see that these two fall into the one exception where we get a most inference (A-most-B; B → C is the one time this happens), so we can infer:
Skilled artist-most-Good at abstract reasoning

This does share one term with the conclusion (Good at abstract reasoning), and the other term in the conclusion (Famous) shows up in the third premise. However, we can't draw an inference from a some and a most statement, so we're at an impasse here.

Forgetting about that third premise for a second, what statement would allow our inferred statement to build to the conclusion? Well, we need a most or conditional statement to get an inference from a most statement. They'd need to share the term that isn't in the inference we're trying to draw, and the new statement would need to bring in the new term in the inference that isn't yet established.

That leads us to an anticipation—we need either:
Skilled artist-most-Famous
Skilled artist → Famous

If we add either of these to the stimulus, it combines with the inference from statements #1 and #2 to lead to the conclusion.

Yes, this is a stronger version of the third premise! It's not common that we end up throwing out one premise is Strengthen with Sufficient Premise questions, but here we are. And since these questions generally have correct answers that just bridge the gap, we can anticipate the most version will be correct.

Answer Explanation:
Skilled artist-most-Famous. This answer matches our anticipation. With the inference from the first two statements, this answer allows the conclusion to be inferred.

Key Takeaway:
Strengthen with Sufficient Premise questions featuring quantifier statements are hard enough without them pulling shenanigans, but here we see shenanigans were pulled! The correct answer ended up being a stronger version of an existing premise. In general, for quantifier or conditional Strengthen with Sufficient Premise questions, if there's a premise that can't be built into a chain or doesn't allow for inferences, act as if it doesn't exist and find an answer that would otherwise bridge the gap between the premises and conclusion.