PrepTest 126

Incorrect. While we can infer that Zack's offers half-priced coffee on almost every Wednesday, it could be the case that they offer half-priced coffee every Monday (give people that pick-me-up to start off their week), so we can't draw this inference. Since the stimulus doesn't discuss other days, this answer is out of scope.

Incorrect. This answer is a reversal of the most statement, which is an illegal inference (we can reverse only some statements).

Incorrect. Since we don't know how often Zack's offers half-priced coffee when there isn't a poetry reading, we can't draw this inference.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
Wednesday -most- Free poetry reading at Zack's
Poetry reading scheduled at Zack's → Half-priced coffee all day at Zack's

Answer Anticipation:
This stimulus seems straightforward—a couple of conditional statements that overlap! However, there are two subtle issues here that we need to be aware of.

First, the opening statement isn't conditional—it states that the free poetry readings are almost every Wednesday. We can treat that as a most statement, but we should remember that it's a bit stronger than the normal most statement.

Second, the second sentence discusses days when there is a poetry reading, whereas the first statement is about free poetry readings. These concepts are related, but they are distinct. In this case, the latter (free poetry readings) is completely included in the former (poetry readings), but there could be poetry readings that aren't free. In other words: Free poetry reading → Poetry reading, but it's not true that Poetry reading → Free poetry reading.

With that in mind, let's see what—if any—inference we can draw through the combination here. That poetry reading term is where any overlap would have to be. We can say that when there's a free poetry reading at Zack's, there's a poetry reading, so we can rewrite the first statement:
Wednesday -most- Poetry reading scheduled at Zack's

And we know that when a most statement shares a term with the sufficient condition of a conditional, we can combine them to make an inference (if you don't know that, go back and study your quantifier/conditional inferences!). One combination results in a some statement; another yields a most inference. Here, the specific combination leads to a most inference:
Wednesday -most- Half-priced coffee all day at Zack's

There's not many other places for an inference to hide in these two premises, so this should be the correct answer.

Answer Explanation:
This answer matches our anticipation, but it throws in an "if not all." That can seem to throw it off, but it actually means nothing—it's a condition, so it might not be met. Additionally, while Zack's is guaranteed to serve half-price coffee on the Wednesdays when there's a free poetry reading, there's nothing stopping them from doing it on the Wednesdays when one isn't scheduled, as well. So this answer is supported.

Key Takeaway:
When there are two related terms that appear to have a gap between them, see if one of them guarantees the other (and then make sure that guarantee "flows" in a direction that matches the argument). Some terms do allow definitional jumps to be made—if it's hot, it's not cold (but not vice versa); if someone's tall, then they're not short (but not vice versa); and if there's a free poetry reading, then there's a poetry reading (but not vice versa).

Incorrect. Based on the stimulus, Zack's is guaranteed to offer half-priced coffee all day on almost every Wednesday (the ones when free poetry readings are scheduled). However, that doesn't guarantee they don't offer free coffee on other Wednesdays! That's an illegal negation of the statement.