Question 8

Is it because of the Either that appears right after?

@Mehran When was it stated that must introduces a necessary condition? I don't have it in my notes and see it was asked on this message board but without a response. I too was confused on how to diagram the last sentence since "either or" was present yet I recognized it was not in a traditional set up but had no clue what my option was for diagramming until seeing the video.

@Samir-Ghani and @Meredith, Happy to help. The word "must" introduces the necessary condition. Think about it; what does "must" mean? It means "be required to" or "need to," so it means that whatever follows has to occur. This is why it introduces the necessary condition. Here's how we diagram the stimulus: Profitably Sell - >Discount. No High Volume - >No Discount. High Volume - >Cater to Mass Tastes OR Specialized Market Access Looking at the prompt, we're told an additional fact—the bookstore doesn't cater to mass tastes. Using this, we're asked to choose the answer that must be false. We can link our conditional statements up to make a chain. Profitably Sell - >Discount - >High Volume - >Specialized Market Access or Cater to Mass Tastes Since the stem tells us that the bookstore doesn't cater to mass tastes, then we can modify the chain to look like Profitably Sell - >Discount - >High Volume - >Specialized Market Access The correct answer choice will be something that contradicts this chain since this is a must be false question. The chain can be violated by affirming a sufficient condition while denying a necessary condition. Let's look for a contradiction in the answer choices. (D) says, "The bookstore does not have exclusive access to a large specialized market but profitably sells some of its books at below-market prices." (D) contradicts the chain we made because it denies a necessary condition (the bookstore doesn't have exclusive access) while satisfying a sufficient condition (the bookstore profitably sells). Thus, (D) is the correct answer choice. Does this make sense? Let us know if you have any other questions!