Diagram

[natalie_lupo]

I'm having difficulty with reading/applying the logic chain with binary grouping! Any expertise is greatly appreciated.

[noah]

Hey Natalie, Are you creating the correct arrows? Or is it a problem with the questions? It may be that you need to brush up on your conditional logic -- take a look at the chapter on that and re-run some of those drills. Happy to help if you explain a bit of what's making it difficult...

[Hwilliamsvi]

I also have a question here, I set up it, and got 4 out of the 6 correct. I am getting tripped up on the conditional logic with the figs and watermelons, can you show me set up? Because for question 4, I picked B and the answer is C and I'm not sure why that is. Any help would be appreciated.

[aileenann]

You have hit the nail on the head - the challenging constraint in this game is definitely the one relating W, F, and T. In fact, there isn't really a standard way to diagram this, because the problem is that knowing W is in doesn't tell us anything definitively about F and T. Rather, it only tells us that at least one of F and T (and maybe T) has to be in, which means we have to monitor them both. I am attaching my diagram. As you can see, I just put this constraint on the side instead of working it into my diagram.

However, I am not sure that missing # 4 is related to this constraint directly. Let's think about it. If we know that W is out, the only thing we also know for sure is that O is out (contrapositive of one of the other constraints). That leaves four remaining fruit that could be in, except that of the four remaining, two are mutually exclusive - K and T. Therefore it is not at most four but rather at most three kinds of fruit that could be in. Hence, our answer is (C).

Let's think about the problem with (B). What is amiss here is that it's actually possible for the stand to carry only one kind of fruit. For example, we could say K is in, from which we know P is out. We could then choose to have F and T out (the consequence of which is that W has to be out, but we have that already). Hence it doesn't have to be true that there are at least two kinds of fruit that are in.

Does that make sense? Please let me know if you have other questions or comments on this game.

[mcrittell]

How come in the diagram, W is not connected to F|T|both, yet is only put at the bottom?

I noticed in 31.2, and/or set ups that they are included in the diagram.

Thanks!

[ManhattanPrepLSAT1]

The reason W is not connected to F, T, or both is because we aren't certain that W actually implies F. It could be the case that W only implies T. Then again, W might not imply T, and instead might only imply F. The issue here is the "or" statement in the necessary condition of the relationship.

Statements that have "or" in the necessary portion of the conditional relationship cannot be included in the Logic Chain.

Likewise, statements that have "and" in the sufficient portion of the conditional relationship cannot be included in the Logic Chain.

Thus, we simply list them below and make sure to never accept a hypothetical that violates that constraint.

Does that make sense?

[cpmckenz]

Hi, guys,

Maybe I'm missing something, but it seems that the diagram is not longer attached within this thread although it is mentioned as being attached. I'd like to double check my setup.

Thanks,
Colin

[cpmckenz]

In case it's easier to give me a thumbs up or down rather than you folks uploading a diagram, here's mine.

[jh2352]

In the set up, is the fourth rule, "If the stand carries watermelons, then it carries figs or tangerines or both", considered one of the compound conditional rules, in which we should write it to the side? How would one suggest setting this up?

[christine.defenbaugh]

Hey all! Looks like our original diagram was eaten by the interweb gods, so I've made it anew!



jh2352, yes, this rule is an unsplittable compound conditional. Any conditional with an "or" in the necessary, or an "and" in the sufficient will be unsplittable. Here, we can't conclude the specific result of W being in - might mean F is in, might mean T is in, or it might mean both are in!

It's generally easiest to simply notate these rules to the side of the logic chain (with an asterisk to remind you when they get triggered!). Fortunately, there are not typically very many of these rules popping up in conditional grouping games.

I hope this helps!

[jh2352]

Hey all! Looks like our original diagram was eaten by the interweb gods, so I've made it anew!



jh2352, yes, this rule is an unsplittable compound conditional. Any conditional with an "or" in the necessary, or an "and" in the sufficient will be unsplittable. Here, we can't conclude the specific result of W being in - might mean F is in, might mean T is in, or it might mean both are in!

It's generally easiest to simply notate these rules to the side of the logic chain (with an asterisk to remind you when they get triggered!). Fortunately, there are not typically very many of these rules popping up in conditional grouping games.

I hope this helps!

That was perfect, I was just a bit confused because a former post had the rule similar to this diagramed. And I was curious if that also was a compound conditional statement, and if so was that the proper way to diagram it? Here is the link if you get a chance (someone uploaded the diagram):

diagram-t33.html

Thanks again!!