Grouping Logic Games

flounder
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Grouping Logic Games

Postby flounder » Wed Mar 30, 2011 9:44 pm

Are kicking my ass. I was going through the Powerscore book at such a good speed, understanding everything and so forth. Now I dont understand why I got something wrong AND I dont understand the explanation of why I got it wrong.

cubswin
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Re: Grouping Logic Games

Postby cubswin » Wed Mar 30, 2011 9:48 pm

flounder wrote:Are kicking my ass. I was going through the Powerscore book at such a good speed, understanding everything and so forth. Now I dont understand why I got something wrong AND I dont understand the explanation of why I got it wrong.


Are all of the grouping games troubling you? Did you struggle with the birds game in particular?

dakatz
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Re: Grouping Logic Games

Postby dakatz » Wed Mar 30, 2011 9:51 pm

This is where conditionals, and making deductions are most key. Grouping games are based on mastery of conditionals, so make sure you have that completely down or else it will be hard for you to understand how the rules fit together. Like always, take some time to diagram everything and make deductions. Just one or two key deductions and the whole game may fall into place. If you have any specific questions you would like assistance with, PM me (but since I don't have my LSAT books here, just type up the rules and the question/choices, and I'll be very quick to help)

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leche
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Re: Grouping Logic Games

Postby leche » Wed Mar 30, 2011 11:02 pm

Ugh me too. What's weird is if there are multiple stacks or groups to keep track of (days of the week, AM/PM, different subgroups) I actually do better. It's the ones where there is no setup and it's all rules and inferences (like the birds one, or the friends in the photo one) that kill me. I always seem to miss some huge key deduction. Any tips?

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JamMasterJ
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Re: Grouping Logic Games

Postby JamMasterJ » Wed Mar 30, 2011 11:07 pm

leche wrote:Ugh me too. What's weird is if there are multiple stacks or groups to keep track of (days of the week, AM/PM, different subgroups) I actually do better. It's the ones where there is no setup and it's all rules and inferences (like the birds one, or the friends in the photo one) that kill me. I always seem to miss some huge key deduction. Any tips?

Give me an example, or PM if you prefer. LG is the only part of the test I'm good at so I (hopefully) can help you with any questions you have

bp shinners
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Re: Grouping Logic Games

Postby bp shinners » Thu Mar 31, 2011 2:02 am

I generally find that two things help with grouping games:

First, go over (and over) (and over!) (seriously, over again) the relationships, what they mean, and how to quickly convert the English to the logic. Learn how they interact and how to combine them. Then do it again. Most people who have problems with grouping games haven't spent nearly enough time figuring these out.

Second, realize that in a grouping game with only two groups, for any player, there are 2, and ONLY 2, scenarios: one where that player is in group A and one in group B. You can usually get a pretty decent set of scenarios by picking the most restricted player and playing each scenario out. A very general rule, but it can open up a lot of doors if you're stuck (on some games).

flounder
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Re: Grouping Logic Games

Postby flounder » Thu Mar 31, 2011 8:21 am

friends in the photo one

SUCKED

Professors who learn a language

SUCKED EVEN MORE

I know I need to just keep practicing. The upsetting thing was I was ripping through the book and came to a CRASHING halt with grouping games. I dont have a lot of time to study either. I am 38, I work 40 hours a week, I have an internship for my paralegal program and I am married. Not a lot of time left.

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leche
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Re: Grouping Logic Games

Postby leche » Thu Mar 31, 2011 10:18 am

JamMasterJ wrote:
leche wrote:Ugh me too. What's weird is if there are multiple stacks or groups to keep track of (days of the week, AM/PM, different subgroups) I actually do better. It's the ones where there is no setup and it's all rules and inferences (like the birds one, or the friends in the photo one) that kill me. I always seem to miss some huge key deduction. Any tips?

Give me an example, or PM if you prefer. LG is the only part of the test I'm good at so I (hopefully) can help you with any questions you have


Ok. PT 36, S4 - the one about the fruit stand. I diagrammed the rules as:

K <-/-> P
-T --> K (and the contrapositive -K-->T)
O --> P (contra: -P --> -O)
O --> W --> F and/or T (contra: -F and -T --> -W --> -O)

For my inferences this is all I have:
P --> T (with a big question mark by it because I wasn't sure if my process was valid: -T --> K --> -P; -T --> -P; and then the contra P -->T)
O <-/-> K


I finished the game in 7:20 which was cool but I ended up missing two. (Question 2, which I narrowed down to A and D and guessed incorrectly on, and question 4 which I stupidly made a wrong inference about pears on) After I went back and looked at the questions I was clearly able to see why I missed them but I can't do that on test day! Was I missing an inference that would have made my life easier?

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JamMasterJ
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Re: Grouping Logic Games

Postby JamMasterJ » Thu Mar 31, 2011 12:22 pm

First. your contraposative of -F and -T --> should actually be -F OR -T --> -W
set up is:
K </> P
-T --> K -K-->T Therefore Either K or T or both is in
O --> P and W
W --> F and T or both
P --> T is correct. K and/or T must be in, and if P and K can't be in together, then if P is in T must be in.
O </> K
The reason that number 2 is tangerine is becuase the only condition applying to it is that K or T has to be included. Notice that nothing else has anything to do with T and T and/or K is the only condition that states that one or the other MUST be present.

Kurst
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Re: Grouping Logic Games

Postby Kurst » Thu Mar 31, 2011 12:28 pm

PT36 Game 1:

Code: Select all

        ~FT -> ~W
                 \
~T -> K -> ~P -> ~O

O -> P -> ~K -> T
 \
  W -> F/T (or both)

This logic chain neatly captures all of the rules and inferences which follow from them. See either Steve Schwartz or Griffon Prep for an explication of the logic chain method for In/Out games.

And leche, your contrapositive of the fourth rule is correct; disregard JamMasterJ on that point.

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JamMasterJ
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Re: Grouping Logic Games

Postby JamMasterJ » Thu Mar 31, 2011 12:34 pm

oh wow. Brain fart. my bad. I just woke up. Thanks for the catch

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leche
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Re: Grouping Logic Games

Postby leche » Thu Mar 31, 2011 6:06 pm

Wow. I hadn't tried this whole chain logic thing before. It makes SO MUCH MORE SENSE. It doesn't clog up the bottom of the page and it takes so much less time. Thank you!! :D

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mac35352
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Re: Grouping Logic Games

Postby mac35352 » Thu Mar 31, 2011 6:21 pm

flounder wrote:friends in the photo one

SUCKED

Professors who learn a language

SUCKED EVEN MORE

I know I need to just keep practicing. The upsetting thing was I was ripping through the book and came to a CRASHING halt with grouping games. I dont have a lot of time to study either. I am 38, I work 40 hours a week, I have an internship for my paralegal program and I am married. Not a lot of time left.

The games are my favorite part of the LSAT, but I have to say...the friends in the photo game was ridiculous.

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leche
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Re: Grouping Logic Games

Postby leche » Thu Mar 31, 2011 6:27 pm

leche wrote:Wow. I hadn't tried this whole chain logic thing before. It makes SO MUCH MORE SENSE. It doesn't clog up the bottom of the page and it takes so much less time. Thank you!! :D


I just thought of something though. Is it possible to diagram EVERY in/out game like this? Are they written so that all the rules can link up? Because I could see this being pretty tough if that weren't the case.

flounder
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Re: Grouping Logic Games

Postby flounder » Sat Apr 02, 2011 3:09 pm

Okay...
So I went back to the beginning of the grouping section and I took copius notes. For me, writing out what I am reading helps to re enforce concepts. I retook two of the practice tests and did a much better job on them. Also, I understood the explanations. I have come to the realization that I prefer my own version of diagramming and having too many inferences just confuses me. I know the inferences are key, but I cant write out everything because it messes me up. I write out 75% and then make the final 25% in my head and that seems to work better.




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