Setup and Rule Diagrams

[Adam Tyson]

To your first question, gingerale, those inferences come about as a result of the restrictive nature of the J-G-R sequence and that fact that you have to keep GHJ apart from each other and also QRS apart each other. If Q was 4th, it would have to be before S, but not next to it, so S would be 6th and Y would be 7th. Now, where would you put R? There is no place for it to fit!

If S was 5th, R would be forced into the 7th space (because it can never be 1, 2, or 3, and could not be 4 or 6 as that would put it next to S). Y would have to go between at 6, forming an SYR sequence at the end of the order. But then GHJ would all be forced into the first four spaces (along with Q going in there somewhere), and at least two of those would end up next to each other, which is not allowed.

The inference about Y is similar - if Y is 2nd, then S must be 1st and Q must be 3rd. If the first three in order are SYQ, then GHJ all end up squeezed into the last four spaces (along with R), and at least two of them will have to go next to each other. That's why Y can never be 2nd!

Most of these inferences come from trying them out - they are not immediately obvious, and for that reason you might not get them during the initial setup, and that's okay. You can still succeed at this game without them, as long as you discover them when certain questions require you to.

[pmuffley]

Really confused here. "Can" in this situation means that S can only go before Q if Q is third. That would mean that, if Q were placed third in a local question (for example), we should know from the rules that we can place S before Q...but that the rules do NOT force us to do that. It is just now possible because a necessary condition has been met. That is similar, but still very different than a game saying "A is placed before B if B is after C". That is a definite statement. Once the necessary condition is met, we must place A before B. It is not just an option for us. Whether or not this actually impacts the game is not the point I'm making. If we are just diagramming a game, and haven't started any of the questions, this would be how I would think about it whether my thought process is changed by looking at the individual questions.

How can we be told to look for subtleties, and then one smacks us in the face, but we're told to ignore it? I am finding this happens a lot in the forums and in my recent experience with the personal 1:1 tutoring. It is very frustrating (not going to lie). I scored a 171 on the practice test right before this practice test. I say that to make the point that I'm not out here slacking off, and I'm not out here missing logic game questions left and right (although I totally bombed this one, which definitely has me frustrated). I'm upset because there doesn't seem to be a lot of agreement on what subtleties are important and how we should intuitively know which ones to avoid and which ones to pay attention to - especially when I'm given conflicting instructions on which subtleties to ignore and which ones to pay attention to.

gcs,

We already know that S can be earlier than Q, unless something prevents it from happening. So S can be earlier than Q already. What does the statement in the rule change about that? It says that that general permissibility of S being earlier than Q has a restriction - it can happen only if something else also happens. The "can" is not a statement of possibility. That possibility is already cooked into the game. It's not affirming anything. The rule is exactly equivalent in English to "S is earlier than Q only if Q is third."

Robert Carroll

[Robert Carroll]

pmuffley,

It's the "only if" language of the rule that creates a conditional. As I pointed out, in the scenario, anything can go anywhere. The rules can provide only restrictions - the rules cannot allow something to happen that was not already permitted by the scenario. So S "can be earlier than Q" already in the scenario, because it wasn't ruled out. The second rule is putting a restriction on that pre-existing possibility: "only if Q is third". As I said, this is just logically equivalent to a conditional that says "S is earlier than Q only if Q is third."

In your example, you describe "B is after C" as the necessary condition. It's not, though - you use the sufficient indicator "if", all by itself.

There are not subtleties being ignored here and this case is completely consistent with all other cases. I don't see any point dwelling on the word "can" as the conditional here can be restated without that, without losing any meaning at all: "S is earlier than Q only if Q is third." The stylistic, not substantive, choice of the test makers to choose to use the word "can" can be completely eliminated by a translation, and then a diagram of the conditional.

Robert Carroll

[ealanclos]

Hi powerscore,

Are there any games similar to this one that I can use to practice? I really struggled with this one but I understand better after reading the explanations.

Thanks,

Emily

[Administrator]

Hi Emily,

Thank you for the question! One of our veteran instructors, Kelsey, answered your same question earlier in this thread, so I am including her response here for reference:

"If you want to test yourself out on some difficult games, I recommend checking out our list of "Killer Games" here: https://www.powerscore.com/lsat/help/lg ... -games.cfm

There aren't a lot of Advanced Linear, Balanced games on the list because, as you've seen, usually those games are not as challenging. But you should definitely check out PT2 October 1991 Game #4: Dog Show if you haven't already! I'd also recommend checking out some of the difficult Unbalanced Advanced Linear games since they typically also rely on a lot of Not Law inferences. But challenging yourself with any of these games can help you learn about and practice making tricky inferences. That said, remember that these games are not typical and getting the basic game strategies and skills down is most important."

I hope this helps.

Thank you!


Julie Lipscomb
Director of Tutoring and Admissions
PowerScore Test Preparation
1-800-545-1750

[cgleeson]

Good morning,

I have been trying to understand the the "S -> Q ->If and only If Q3" rule. Dave states that be cause of this rule Q cannot be 7th. It took me a while and I finally think I get it. Please correct my reasoning if need be.

Because of the contra positive of this statement Q -> S hence, no possibility of Q in the 7th spot could exist.

This rule I had 1/2 right and because of that I did poorly on the first go. Dave was right as this being the most difficult game of the test, however I thought it to be a lot of fun too.
Thank you in advance for any insight into my reasoning above.

[Adam Tyson]

You're correct about that contrapositive, Chris - if Q is not 3rd then it must be before S, so Q cannot be 7th. That also means it cannot be 6th (because then it would be next to S and S would not be before Y) or 5th (again, that would force Q next to S, with 5-6-7 being QSY). Q 4th also gives us problems, because when Q is 4th, S must be 6th and Y must be 7th, and you have no place for R. There are a LOT of inferences about Q that follow from that rule!

[nivernova]

"But, since S already cannot be second, we can infer that Y cannot be second due to the third rule."

I don't understand why Y cannot be second just because S cannot be second....

[Adam Tyson]

That explanation could use a little more detail, nivernova, because it's about more than just the inference that S cannot be 2nd.

Think about the three articles on finance, GHJ. None of them can be next to each other. That means you will need at least 5 consecutive spaces open to spread those out. The same is also true for the three articles on nutrition, QRS.

Now, if you put Y 2nd, S has to go first. Putting S first forces Q to be third. That gives you a starting sequence of SYQ, leaving only 4 more spaces to place all of the finance articles. That won't work, because it will force you to put at least two of them next to each other. That's the real reason why Y can't be 2nd: it's the whole domino effect that is has on all the other variables.

You'll notice that a similar domino effect happens if you try to put Y third. That will either force S to be before Q, which would require Q to be third (a conflict) or else put Q 1st and S 2nd, next to each other, which is also a problem. Thus, Y can't be third, either!

[ronaldofenomeno]

Hi,

I am not sure to understand that part: "But, since S already cannot be second, we can infer that Y cannot be second due to the third rule."

Couldn't it be S1, Y2, and Q3?

Thanks in advance.