#12 - Local, Rule Substitution

[kristinaroz93]

I see, so the either/or lanaguage for rule 1 means one is in at all times. So if it had said "if K is in then N is not", could we then presume then in that scenario that both can be out at the same time?

And thanks so much for your swift response, I really appreciate it!

[jeff.wren]

Hi Kristina,

Just to be clear, if all we had was the rule that you mentioned "if K is in then N is not," then it would be possible for both K and N to be simultaneously out. The rule that you mentioned is basically the "not both" rule, which can be diagrammed (K -> not N) and (N -> not K) by the contrapositive, or combined in one statement using the double not-arrow (N<-|->K).

Basically, whatever is on opposite sides of the double not-arrow cannot occur at the same time. In this case, the one thing that the rule prohibits is both K and N being selected together. The other three possibilities: just K, just N, or neither selected are all possible.

Hope this helps.

Best,
Jeff

[kristinaroz93]

Thank you so much Jeff! You have been very helpful=)

[Nfontes93]

Hi this question was particularly difficult for me as are most suspension questions and I only answered it correctly by luck. I was running out of time and narrowed the choices to C or D, but I am unsure how to approach these questions in general. I assume this is not one that I should stress about too much as it is more time consuming, but just for future reference when the question stem asks to substitute a rule, should I be looking for the answer choice whose rule when applied implies the suspended rule? So in other words for this question, should I be looking for the answer choice that will eventually imply the original rule J--> K?
And as a whole, do you have any suggestions for how I can approach these questions in a more timely manner?

[Dave Killoran]

Hi N,

A few things for you here. In your Online student Center, go into the "Lesson and Homework Supplements" section, then to Lesson 11, and then it should be the very last link on the page (I'm pretty sure that's where it is, but if it's not there then poke around a bit. I'm doing this from memory ). That section should help you feel more comfortable with this question type. This scenario, where they suspend a rule and then request that you replace it, is all about creating the same result or effect created by the original rule. So, although a rule that stated J K in other terms would be correct, they don't have to go that route. Any rule wording that results in the same operational effect will work. That idea is discussed in the article I reference above.

In general, these questions are difficulty, but they get easier after you have a chance to review several of them together, and see the range of what the test makers do in these .

That should be a solid start, so please check that out and let me know if it helps. Thanks!

[al_godnessmary]

In your Online student Center, go into the "Lesson and Homework Supplements" section, then to Lesson 11, and then it should be the very last link on the page (I'm pretty sure that's where it is, but if it's not there then poke around a bit. I'm doing this from memory ). That section should help you feel more comfortable with this question type. This scenario, where they suspend a rule and then request that you replace it, is all about creating the same result or effect created by the original rule. So, although a rule that stated J K in other terms would be correct, they don't have to go that route. Any rule wording that results in the same operational effect will work. That idea is discussed in the article I reference above.

Maybe it's just me but I didn't seem to be able to login to my online student center at all...at least it seems to be routing me back to the login page without even an error message. I also struggle more with replacement/substitution questions and was wondering if there were any things in particular I really ought to be looking out for.

[Jon Denning]

Hey al_godnessmary,

Thanks for the follow up! If you don't mind, shoot us an email at lsat@powerscore.com or give us a call tomorrow at 800-545-1750 and we'll help you get logged in. Once you're in the Online Student Center the discussion Dave references above should go a long way toward resolving any confusion/difficulty you still face with Suspension/Substitution questions

So sorry for any inconvenience, but I promise we'll get you sorted out!

Jon

[jackbenimble106]

Good morning,

I'm trying to get a grasp on how I should approach substitution questions like these and one thing caught my eye here.

The first two rules combined result in the inference J N. Substituting the rule in answer (D) for the first rule gets you the inference K N when combined with the second rule, which is the same as the original first rule itself. When answering substitution questions in Logic Games, should I look for an answer choice (i.e. new rule) that when substituted for a given rule results in an inference that is the same as the rule for which it was substituted?

That might not have been clear, so let me try to diagram exactly what I mean in a kind of quasi-algebriac fashion. See below:

K N + J K = J N

X+ J K = K N

Answer = J N

In those terms, is this question basically asking me to solve for X?

I hope that makes sense. Let me know if I need to clarify.

[Adam Tyson]

That is one of a few great ways to approach these otherwise challenging questions, jackbenimble106! If the rule in question had some powerful inference, sometimes the inference you got from the rule can substitute for the rule because it allows you to then work back and infer the original rule. But beware, this won't always work! If in some other game you had a rule that if P is in, Q is out, and that allowed you to infer that if P is in, R is in, that would not necessarily mean that a rule of if P is in, R is in could sub for the original rule about P and Q. It all depends on how that inference was made. So you have to check to see if you can start with the inference and work back to the rule or not.

It does, however, work frequently, and can allow you to quickly cut to the right answer! And even if it doesn't turn out to be correct, it's usually an easy answer to identify and quickly test and then either select or eliminate. Look for the answer that captures the inference!

[jackbenimble106]

That is one of a few great ways to approach these otherwise challenging questions, jackbenimble106! If the rule in question had some powerful inference, sometimes the inference you got from the rule can substitute for the rule because it allows you to then work back and infer the original rule. But beware, this won't always work! If in some other game you had a rule that if P is in, Q is out, and that allowed you to infer that if P is in, R is in, that would not necessarily mean that a rule of if P is in, R is in could sub for the original rule about P and Q. It all depends on how that inference was made. So you have to check to see if you can start with the inference and work back to the rule or not.

It does, however, work frequently, and can allow you to quickly cut to the right answer! And even if it doesn't turn out to be correct, it's usually an easy answer to identify and quickly test and then either select or eliminate. Look for the answer that captures the inference!

Understood. Thanks!