@DeborahJimenez I'd be careful! I think you are confusing sufficiency and necessity.

For me, I started with translating the last sentence into Lawgic first because that was the clear conditional statement with indicators. When you do that, you get:

If no advantages --> not common

Which in abbreviated Lawgic is just:

/Advantages --> /Common

As we've also learned, we can take the contrapositive of that Lawgic statement and it should still be true:

Common --> Advantages

Which translates to: If bilateral symmetry is common, then it does confer such advantages.

Then, moving to the rest of the stimulus, we see that Anatomical bilateral symmetry IS common, so it therefore it SHOULD confer such advantages, and we know that is a valid conclusion to make because it follows the contrapositive statement we just derived from the original statement.

Your conclusion "Advantages --> Common" is not a conclusion that can be drawn from the conditional logic we have here. The stimulus isn't saying that if you have this survival advantage then it is a common thing to have, but that's what your Lawgic implies!

I'd be curious to see your mapping that led you to the correct answer, but definitely be careful about making the sufficiency necessity confusion!

@AkshayaAnnampedu For me, what give away that it is an "inclusive or" is the fact that there's no language in the sentence making it exclusive. That sounds confusing, but let me explain in comparison to the exclusive example "You must eat either the steak or the cod, but not both"

In Jon's example, he HAS to enroll in either Econ or Polisci, but there's nothing excluding him from taking both. What initially tripped me up was using Lawgic. With Lawgic, we get:

/Econ --> Polisci

/Polisci --> Econ

This mapping of the sentence makes it seem like "oh if he isn't taking econ than he must be taking polisci or vice versa." It seems like it's cut and dry that he's either taking one or the other, but nowhere in the sentence does it say that he's not allowed to take both. Lawgic helps us understand that at the very minimum he HAS to be taking one of those classes, and we can understand that by saying "okay, if Jon isn't taking polisci, then he HAS to be taking econ." However, there's also a world in which he's taking BOTH of those classes, but since we didn't map that out via sufficiency necessity conditions, it was harder (at least for me) to understand that option.

If you compare that to the exclusive example with cod and stake, you can see that really the only difference is the "but not both" at the end of the sentence. You can literally take that at face value - in no world are you allowed to have both the steak and the cod. Because of that, you know that this is an exclusive or because it isn't like the example with Jon where he had the possibility of potentially taking both classes. So, if you can clearly see that there are only two options you can't stray from, then the Group 3 "Negate Sufficient" rule is not applicable anymore.

I'm not sure if this helps with your question about context, but this is how I mapped it out in my head in a way that made sense!

@hataie This might not be super helpful, but when you try replacing the referential with the referent, in this case it would be "The most successful novels have been the novels that deliver etc etc" which just sounds more natural than saying "The most successful novels have been the successful novels that deliver etc etc" which sounds a little redundant. It's not a technical way to approach understanding the specific phrase that is being referred to, but I think intuitively it makes a little more sense to me if the referent is just "novels." I hope that helps a little!

@hataie In the case of this argument - the Tigers Argument - the assumptions JY discusses aren't stated in the argument. In the original argument, we only know one premise: "Tigers are very aggressive and can cause serious injuries to people." The assumption in the diagram "Aggressiveness and the potential to cause injuries to people ARE factors that make an animal unsuitable to keep as a pet" is one of the so called "forgotten premises" that JY is referring to. That statement is nowhere to be found in the original argument, but it's an assumption we are making when we say that the conclusion that "not every mammal is suitable to keep as a pet" is supported by the original premise. As JY explains, it's an assumption because if we were to say that aggressiveness is NOT a factor for pet suitability, then the support between the OG premise and conclusion is weakened a lot. When I evaluate in the framework that the assumption is false, then I see that it doesn't really matter whether Tigers are aggressive or not because aggressiveness has nothing to do with how suitable a pet is. You can't reasonably infer that "Not every mammal is suitable to keep as a pet" if your only support is that tigers are aggressive, but aggressiveness has nothing to do with suitability. At that point, you just have two kind of unrelated statements that make it hard to see why this would be an argument. You could ask yourself: why aren't all mammals suitable to keep as a pet? If the assumption we're making about aggressiveness is false, then the fact that tigers are aggressive doesn't help you answer that "why." I think this will also make more sense in the context of assumption questions types, where you might be asked whether an assumption is strengthening or weakening an argument, but I hope this isn't too convoluted of a response and helps a little!

#Feedback #Admin Part of the explanation for AC A is incorrect. JY says that "it was Einstein" in reference to the first scientist to describe the mechanism by which the sun generates heat (nuclear fusion), and attributes that as one reason why the AC is wrong. However, the passage says that the discovery of nuclear fusion relied on Einstein's EQUATION, not that he came up with the idea himself. So even though we have no proof that Cecilia Payne was the first scientist to discover Nuclear Fusion, we also have no proof that it was Einstein. We simply don't know who invented Nuclear Fusion based on this passage alone.

@7SageTutor #Feedback I think you meant to say Answer choice B!