Logical reasoning PrepTest 138 · Section 2 · Question 18

Incorrect. This is an illegal reversal of the first conditional.

Incorrect. There's no way to make inferences about people who aren't delegates or party members, as that would involve the contrapositive of the first statement, but that couldn't be combined with the some statement since we can't contrapose those.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
(1) Delegate to convention → Party Member
(2) Delegate to convention-some-Government official at convention
(3) Government official at convention → Speaker at convention

Answer Anticipation:
A Must Be True question with a mix of conditionals and quantified statements? Time to dust off our skills on making inferences using them.

Taking a look, each of the conditionals has a sufficient condition that overlaps with a term in the some statement. That's a combination that's allowed—after all, if all of a group has a feature, and some of that group has another feature, then some members of the group must have both. The question is going to be if we can combine all three to reach an inference, as that's likely to be the correct answer if possible. So let's start by combining 1 and 2:
Party member-some-Government official at convention

Taking a look at that, it shares a term with the third statement, and it's the sufficient condition of the conditional that shows up in the some statement. That's the same pattern as our initial inference, so we can make the same type of inference:
Party member-some-Speaker at convention

Answer Explanation:
Just as we anticipated! This answer draws an inference by combining all three statements.

Key Takeaway:
Learn how to make valid inferences from conditionals and quantified statements—it's worth a couple points on the exam!

Incorrect. This answer is an illegal reversal of the second conditional.

Incorrect. This answer would require chaining only conditionals to get another conditional ("Every"), but the conditionals don't directly overlap.