Diagram

[noah]

Here's the diagram I used for this game. I can explain any specific question, but I think if you can figure out how to get to this diagram, you're more or less there.

There's one big inference you need to make: if city X is connected with city Y, then city Y is also connected with city X.

Also, to begin with, what's the maximum amount of connections a city can have? Four.

Other initial inferences: M is given to you -- it can only connect with one city -- therefore, H cannot connect with M because it would force M to connect with a second city (and so you have to note that H cannot "receive" M and M cannot "receive" H). H cannot connect with T (and vice versa) because of the given constraint.

Take a look, then take a break and see if you can come up with the same diagram.


Tell me if you have any questions about this. - Noah

[gregory.mortenson]

This game was very tricky for me. It took two attempts to get the diagram correct and even then the questions were an arduous slog (questions 14-16 especially).

Is it common to see an Open Assignment game like this where you're matching "within" one group (as opposed to matching one group to another group)? This was the first of this type that I had seen....

[noah]

It's a rather rare version of open assignment games, but one you should become comfortable with. It can be tough to remember to keep in mind the bi-lateral nature of each relationship.

Take a look at this one for a bit more practice: http://www.atlaslsat.com/lsat-logic-game-4.cfm

[jaydizzle]

This game is driving me mad. I started it off quite similarly to the posted diagram. I made 3 diagrams to outline 3 scenarios. One where P and T are connected, one where P and V are connected, and finally one where this is not the case. This worked well for the first three questions. Despite the explanations I still can't do questions 14 through 17.

[noah]

OK, I'll take a look. Can you post what the frames have in them? Maybe you overlooked an inference.

[jaydizzle]

I have the same scenario as the one you posted as my #1. Then my second one looks the same as the one you posted except I have T with P. So under P, I filled in a T and took out one slot since V can't go in. Under T, I also put in a P. Under V, I took out one slot since P can't be there. It's the same diagram as you had except for these things to account for PT.

My third one is almost the same, except it takes account for PV. I put in V under P, and took out one slot since T cannot go there. I took out a slot under T since P cannot go there. Finally, I filled in a slot under V with P.

So, basically my setup was exactly like yours except I had 2 more with PT and PV.

I just have troubles with the questions. It takes me so long to visualize anything, and it is almost as if I have to try each of the answer choices.

[jaydizzle]

Hmm, I am going to give the Logic Challenge one a try since it is similar. The thing that worries me about these games is that they are so rare they are bound to pop out again. I believe a lot of people consider them to be mapping games. I took a second look, and I am doing alright. It's just it is rather time consuming.

[noah]

I looked over my diagram and notice that I did not include these notations:
H --> T
PV --> ~ PT
PT --> ~ PV

(I guess I was so focused on showing the open board).

Thinking about your frames, I'm not sure they are worth it as I don't see that each one creates a cascade of inferences. Maybe I'm missing something though.

This is a very tough game, and would no doubt take anyone but the greatest game geek a lot of time. It's one that's worth doing every week or so to exercise your brain.

It sounds like you feel comfortable with it at this point - I'm happy to discuss any questions you're still wrestling with. Perhaps you'd like to write up how you solved some of those later questions to truly slay this dragon.

I just figured out a quick way to approach #16. Since there are 13 open slots, the maximum number of pairs might be 6, and then because of the PT --> ~ PV rule, we have to eliminate one pair. If I was short on time, I might pull the trigger at that point, if I had some in the bank, I would probably spell out the scenario to make sure I'm not missing any restrictions.

Anyway, tell me if you want to keep working on this one (or post an explanation and I'll look it over). - Noah

[dababbott]

thanks, Noah. #&@*^$@ Zephyr Airlines, I'm never flying them again.

[noah]

thanks, Noah. #&@*^$@ Zephyr Airlines, I'm never flying them again.

LOL

Try out game 4 in our Logic Challenge archive - it ends up working some similar muscles, but, considering your reaction to the Zephyr game, might leave you never going to a park again...

[geverett]

Noah,
I saw this game 6 months ago. Bit the dust on it, and have been procrastinating on really diving in on this for some time. I have been finally forced to come to grips with it this week b/c it was on the PT I just took. Your diagram really made this game make sense in a way it never has before. Seriously you rock. I will do the logic game challenge you guys have on your site tomorrow to try and further cement the concepts behind tested here. Thank you!

[noah]

Thanks! Glad it was helpful.

BTW, next time my wife and I are having an argument, I'm going to tell her you said I seriously rock.

[geverett]

Dude,
having the knowledge of LSAT reasoning totally has changed the dynamic of the arguments my wife and I have. I can't say it's been a change for the better haha, but it definitely has changed.

For example:

My wife: You never do ________

Me: Really? Never? Maybe sometimes I never do _____. But to say I never do______ is quite a bold statement. haha.

haha I should probably stop with the LSAT logic in any future marital disagreements.

[noah]

Funny that we're talking about this - look what Cory just posted: http://www.manhattanlsat.com/blog/index ... 08/11/895/

[matthewyoung2008]

I think this problem is best tackled without a 5 x 4 fill-in table.

If we were assigning buildings to food trucks, or genres of music to different CDs, that is, one type of thing to another type of thing, I would use this kind of setup. But the reflexive nature of this problem means I can write up all my inferences into the table and still have it looking very empty and incomplete (12 empty slots!).

I would just draw spider diagrams / hypotheticals that link one letter to another and brute-force the problem. It's faster and not a time-sink when under pressure.

[hall.briandavis]

I did this with about 10 minutes left in a timed PT, and got a total of (-2) both missed on this game. Would have been (-0) if I had another minute or two:) While I didn't do any real set up b/c it was confusing at the moment, I really like the open board assignment. Tricky part is recognizing to use it in this situation.

I did come across one inference that guided me through. Seems vaiid, if not, need a geek to shoot it down.

Essentially we know that H and M must have exactly one element in common either P or V. Rule 3 tells us that a H and M have an element in common. Initially it seems this can only be P, V, or both because M cannot have two connections. We then see from rule 4 that it cannot be both PT and PV so, H and M must both be connected to either P or V.

From this you can create pretty powerful frames. Unfortunately at the time I did not see this and quickly sketched the inference as seen below.

I used a block system where
H
---> P or V (exclusive or) and ---> arrow signalling that both
T H and T have the same
common link.

My 2 cents as an amateur is to remain flexible as the books advise. Don't get freaked out by the seemingly new problem type. Stay confident, attack problems that seem easy, and keep trying to make deeper game changing inferences as you move along.

[ManhattanPrepLSAT1]

Initially it seems this can only be P, V, or both because M cannot have two connections. We then see from rule 4 that it cannot be both PT and PV so, H and M must both be connected to either P or V.

Maybe I'm misunderstanding your inference, but isn't it possible for M to be connected to T?

[dkuritz]

For some reason I am unable to view the diagram that was already posted. If someone could post the diagram again that would be greatly appreciated. Thank you!

[ManhattanPrepLSAT1]

So strange, I see the diagram above just fine. But here it is again!

[andrewgong01]

So strange, I see the diagram above just fine. But here it is again!

I seem way off in this game. I didn't see this as a grouping game at all and even from retrospect I don't think it is a good example of a grouping game.... I saw it as one of the transpositional/ rouge game (like the PT72 Summit Company) where it was just drawing arrows to connect and a bit like the computer virus game.

To me it seemed like this game was not set up for grouping because the rules seem to blend more easily where you can draw simple diagrams like
P-T | M-V-H and then draw an arrow that links T with V which seems to give a better visualisation of the game board than a grouping board. This way the Big inference cited earlier "if city X is connected with city Y, then city Y is also connected with city X. " wouldn't need to be infered because it is on the diagram directly.

In total this method of just drawing free diagrams took me roughly 10 -11mins. I suspect this method means that the Big Pause is a lot shorter because it took me just 2mins to jump into the question as there wasn't really any framing or considerations to do or distributions. However, it was just drawing diagrams after diagrams for the questions to test the answer choices and with the answers. That said, I did get lucky with time in that some of the correct answer choices were like Bs and As.

Do you think there may be potential shortcomings to treating this as a transpositional/rouge game game board over grouping? I know from retrospect this way of diagraming does not really show us the distribution at all that a grouping board could potentially shed light on and Q16 does test something close to distribution