Logical reasoning PrepTest 149 · Section 1 · Question 18

Incorrect. The argument never establishes that one of these two committees has a quorum, or that the GA will start at either 6pm or 7pm. The GA not beginning at 6pm guarantees the standards committee lacks a quorum, but that doesn't then force the awards committee to have a quorum or the GA to start at 7pm. Short version? not GA starts at 6pm isn't sufficient for anything other than concluding the standards committee lacks a quorum.

Incorrect. The standards committee not having a quorum isn't a sufficient condition for anything.

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

Incorrect. Similar to (A), this answer establishes that the awards committee lacks a quorum, but the stimulus never establishes that at least one of the two committees has a quorum.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Standards committee has quorum → GA starts at 6pm
Awards committee has quorum → GA starts at 7pm

Answer Anticipation:
In a normal Must Be True question with conditional logic, we'd either be chaining statements together or applying a principle to a specific case. Here, however, it appears as if neither of those is the case, since there's no specific case discussed and the conditionals don't appear to chain together.

However, we should dig a bit deeper, and since there are two conditionals that do share some similarities, we should see if some of the terms can be connected even if they're not exactly the same.

Here, there's no real connection between the sufficient conditions. However, the necessary conditions do both discuss when the general assembly is starting. Since it can't start at two different times, we know that it starting at 6pm means it doesn't start at 7pm, and vice versa—GA starts at 6pm → not GA starts at 7pm. And with that established, we can see that a chain does form when we take the contrapositive:

Standards committee has quorum → GA starts at 6pm
not GA starts at 7pm → not Awards committee has quorum

Standards committee has quorum → GA starts at 6pm → not GA starts at 7pm → not Awards committee has quorum

Awards committee has quorum → not Standards committee has quorum

This connection (or the contrapositive) will likely be the correct answer.

Answer Explanation:
This answer reflects our anticipation. If the standards committee has a quorum, then the GA starts at 6, which means it can't start at 7, and so the awards committee must lack a quorum.

Key Takeaway:
When you have multiple conditionals in a question type that generally asks you to chain them together, but there's no immediately apparent chain, take a look at similar terms. There are some implicit connections that the LSAT will often rely on to allow a chain to form even if a link isn't explicitly stated. As long as that link must be true (e.g., something that is cold isn't hot; something that starts at 6pm can't start at 7pm), then it's valid to write it into the chain.