## Grouping Game help

Prepare for the LSAT or discuss it with others in this forum.
proxy

Posts: 42
Joined: Sun Aug 07, 2011 2:24 pm

### Grouping Game help

Hello, after a failed attempt to complete this game under strict time constraints, I managed to sludge my way through it and get all the answers correct. Of course that won't mean crap under timed conditions, and I'm wondering if anyone can help me. I'm struggling to make deep inferences that will help me breeze through the questions quickly.

Each of exactly five persons - Newton, Omar, Peter, Tyler, and Vivian - participates in exactly one of three activities: going to a motion picture, going to a softball game, or going to a roast bbq party. The following conditions must apply:
Newton and Omar do not participate in the same activity as each other, nor does either one of them participate in the same activity as Peter.
Exactly two persons go to a softball game.
Tyler and Peter do not participate in the same activity as each other.
If Newton or Vivian goes to a motion picture, they both go to a motion picture.

I concluded that the following global set up is correct (Symbols based on Powerscore Logic Games Bible).

Distribution
3-2 or
2-2-1

variables :NOPTV

N <--|--> O
N <--|--> P
P <--|--> O
P <--|--> T

Nm or Vm ---> (N <--> V)

Now I did see the following inference when working through one of the questions: T <--|--> V.
But this didn't occur to me until after I drew a series of diagrams, which I won't have time to do during the test. And only just now as I am typing this do I see that the 3-2 distribution is not possible.

My success rate during actual timed tests on this section is all over the place, primarily because I'm not as prepared as I thought for grouping games.

If someone would be kind enough to guide me through the appropriate set up of this game, I would greatly appreciate it.

Edit: changed to avoid copyright violation.
Last edited by proxy on Sun Aug 07, 2011 6:06 pm, edited 1 time in total.

aevea

Posts: 16
Joined: Tue Aug 04, 2009 12:19 am

### Re: Grouping Game help -lsat 26 - Section 1: 3rd LG (13-18)

Notice the triple negation in the first rule. You've only got 3 groups, so dedicate a "slot" for each group to those 3 guys: maybe something like: N/O/P. That should make the game a whole lot easier--now you just have to worry about T and V in the remaining slots.

lrslayer

Posts: 576
Joined: Mon Jul 11, 2011 10:38 am

### Re: Grouping Game help -lsat 26 - Section 1: 3rd LG (13-18)

Posts: 394
Joined: Tue Mar 08, 2011 12:19 am

### Re: Grouping Game help

Hey, i'm actually just diving into grouping too, so i'll give it a crack:

Like aevea, i noticed N-O-P need to been in different groups, so 2-2-1 is only option with double slot guaranteed for softball.

Also noticed that since T can't be with P, it must be with O or N.

__ (__) __ T,V*
(__)(__)(__) P,O,N*
M....S....R

Also the conditional suggests that if either N or V were to sneak into M's slot, the whole game is decided for because P can't be with T.

Hope that helps, let me know if I missed any inferences!

typ3

Posts: 1362
Joined: Sun Feb 28, 2010 12:04 am

### Re: Grouping Game help

proxy wrote:Hello, after a failed attempt to complete this game under strict time constraints, I managed to sludge my way through it and get all the answers correct. Of course that won't mean crap under timed conditions, and I'm wondering if anyone can help me. I'm struggling to make deep inferences that will help me breeze through the questions quickly.

Each of exactly five persons - Newton, Omar, Peter, Tyler, and Vivian - participates in exactly one of three activities: going to a motion picture, going to a softball game, or going to a roast bbq party. The following conditions must apply:
Newton and Omar do not participate in the same activity as each other, nor does either one of them participate in the same activity as Peter.
Exactly two persons go to a softball game.
Tyler and Peter do not participate in the same activity as each other.
If Newton or Vivian goes to a motion picture, they both go to a motion picture.

I concluded that the following global set up is correct (Symbols based on Powerscore Logic Games Bible).

Distribution
3-2 or
2-2-1

variables :NOPTV

N <--|--> O
N <--|--> P
P <--|--> O
P <--|--> T

Nm or Vm ---> (N <--> V)

Now I did see the following inference when working through one of the questions: T <--|--> V.
But this didn't occur to me until after I drew a series of diagrams, which I won't have time to do during the test. And only just now as I am typing this do I see that the 3-2 distribution is not possible.

My success rate during actual timed tests on this section is all over the place, primarily because I'm not as prepared as I thought for grouping games.

If someone would be kind enough to guide me through the appropriate set up of this game, I would greatly appreciate it.

Edit: changed to avoid copyright violation.

Imo Manhattan LSAT has a better method for grouping and coming up with things. I refer to it as the pinball method. Grouping games used to waste my time on LSAT questions but they actually are some of the easiest. Powerscore is mediocre for solving them. My suggesiton- buy a used Manhattan LSAT games book in the buy/sell sub forum and use that method instead.

Posts: 394
Joined: Tue Mar 08, 2011 12:19 am

### Re: Grouping Game help

Okay so the last few days I've been completely focused on understanding grouping types and categorizing them mentally. I felt that Powerscore's categories were unnecessarily complicated, and felt that Manhattan was oversimplified for certain situations.

I took both sets of categories, synthesized them, and eliminated redundant ones that were attacked with identical strategies. At the end, I had less categories (5) than even Manhattan! Basically what I learned is that there is essentially 2 things they can test you on with grouping games (as much as they are disguised).

1. Conditional Reasoning Linkage and 2. Numerical Structure Restrictions. As I started looking at the rules and question types, it seems that the more they give you on one aspect, the less they will test you on the other aspect. At the same time, having equal amounts of both intensifies the difficulty of visually combo'ing inferences.

For example: Pure Conditional Linkage would be In and Out (Binary-Undefined). Nothing matters but except the conditional relationships between variables. Logic Chain and T-Charts destroy these games easily.

On the other end: Open Repeating Assignment (Partially Defined) focuses on using group's size relation to "force" variables and size possibilities. Open Board really helps to visualize these slot limitations and requirements.

These far ends of the spectrum are dominated by Manhattan's visual representations, but as you go more towards the middle (Closed Assignment), they begin to show limitations. For example: Logic Chain with variable subdivisions < Number Line, and a 10 slot Open Board seems hardly any better than Closed Board when placing 5 variables into 6 slots. With these you are forced to rely on templates or even plug & chug . Powerscore does give you this backbone to fall back upon, and I feel like scanning answer choices for commonalities starts to become crucial towards saving time.

Anyone have any thoughts? I'd love to see if this theory holds up.
*Edit, I just realized this is almost identical to Powerscore going from Undefined to Fixed /facepalm

proxy

Posts: 42
Joined: Sun Aug 07, 2011 2:24 pm

### Re: Grouping Game help

yes, dedicating NOP to separate slots makes things much easier. I don't know why I didn't realize that.

Burnout possibly. Less than 2 months until Oct has caused me to become quite anxious.

proxy

Posts: 42
Joined: Sun Aug 07, 2011 2:24 pm

### Re: Grouping Game help

chadbrochill wrote:Hey, i'm actually just diving into grouping too, so i'll give it a crack:

Like aevea, i noticed N-O-P need to been in different groups, so 2-2-1 is only option with double slot guaranteed for softball.

Also noticed that since T can't be with P, it must be with O or N.

__ (__) __ T,V*
(__)(__)(__) P,O,N*
M....S....R

Also the conditional suggests that if either N or V were to sneak into M's slot, the whole game is decided for because P can't be with T.

Hope that helps, let me know if I missed any inferences!

This is very helpful. Couple of quick inferences that I build off of this.

Pm ---> P1 (P is by itself) this forces the 2 - 2 distribution over S and R

X _ _
P _ _

Ps ---> (P < --- > V). This almost solves the whole game, as it forces N into the R slot, and O into the M slot. T can go over M or R:

T/ V /T
O P N
-- -- --
M S R

Missing the P/O/N split really leaves you in limbo.