#5 - Global, Cannot Be True

[Administrator]

Complete Question Explanation
(The complete setup for this game can be found here: lsat/viewtopic.php?t=26510)

The correct answer choice is (B)

This question asks you to identify the group that cannot march immediately behind G. There are two ways to work out the correct answer to this question: either eliminate those variables that can march behind G, or find the variable that cannot march behind G. Given the considerable amount of information we have amassed in the templates, and in the hypotheticals in the answer choices, the second approach is likely to be the fastest (unless, of course, you have already deduced which variable cannot march behind G).

First, consider the templates: in Template #1, M marches immediately behind G, and thus we can eliminate M from the answer choices. In Template #3, P marches immediately behind G, and thus we can eliminate P from the answer choices.

Second, and especially important if you did not use the template approach, do not forget to consider the hypotheticals created while you answered the questions. Let’s review each hypothetical:


Question #1: In this question we were given the solution J-P-G-F-M-V. This solution eliminates F from the answer choices.

Question #2: In this question we arrived at the solution P-F-G-V-M/J-J/M. This hypothetical eliminates V from the answer choices.

Question #3: In this question we arrived at the solution G/J-F-P-V-J/G-M. If G marched first, this hypothetical eliminates F from the answer choices; if G marched fifth, this hypothetical eliminates M from the answer choices.


Adding all the information together (some of it redundant), F, M, P, and V can march immediately behind G. Thus, only J cannot march immediately behind G, and therefore answer choice (B) is correct.

Answer choice (A): F can march behind G, as proven by the solution to questions #1 and #3.

Answer choice (B): This is the correct answer choice. If J marches immediately behind G, then there is not enough room to place the other blocks without violating one of the rules (try it: the GJ block would have to be placed in groups 1-2, 3-4, or 5-6; in each instance the MP block can be placed successfully, but doing so leaves no room for the FV block).

Answer choice (C): M can march behind G, as proven by Template #1 and the solution to question #3.

Answer choice (D): P can march behind G, as proven by Template #3.

Answer choice (E): V can march behind G, as proven by the solution to question #2.

[PowerSteve]

I tried templates for this game and it seems that I can actually identify the possibilities (I came up with a total of eight possibilities: 3 if G is first, 3 if G is third and 2 if G is fifth...Maybe there are more I neglected?). Once I completed the set-up the questions became very easy to answer.

I am still having difficulty, however, in deciding when to use templates/possibilities. First of all, should I have stopped at templates, or was looking to extend to possibilities a good idea? What should have really tipped me off in this game to go with templates/possibilities? Clearly there are only three possible places that G could be placed, but it seemed that there would still be many different options after simply placing G. Should the block with F and V as well as the distance necessary between P and M in conjunction with the three places G could be, indicate that there would be a limited enough amount of solutions to try templates/possibilities? Or, should I also look to the question types themselves? Does the fact that the questions were mostly local make templates/possibilities more likely or less likely to be helpful than if the questions were mostly global, or are the question types irrelevant?

I'm sorry for all of the questions. I've already completed the course, own the logic games bible and have reviewed the appropriate virtual modules containing the information pertaining to templates/possibilities. Still, I find that reflecting on particular cases and what makes them templates/possibilities worthy (or not) is very helpful (and of course that is something suggested in the LG Bible). I'm afraid, when I see a game like the one we're discussing, to start working with templates because I know that a misuse of templates can be very time consuming. Thanks again for all of your help!

~Steve

[Steve Stein]

Good questions. Identifying all of the possibilities can be extremely helpful, but, as you point out, it becomes less helpful as the number of possibilities begins to branch out.

So, when to spell out all of the possibilities? I would err on the side of not attempting to spell out every possibility as you create your global diagram (local questions will require that specific possibilities get spelled out anyway) unless it is very clear from the outset that the rules will limit the number of possible outcomes to just a few.

I hope that's helpful! Let me know if that answers your questions--thanks!

~Steve

[PowerSteve]

Thanks Steve. Your response does help in advising me to err on the side of attempting templates rather than possibilities. However, I am still curious as to what should have tipped me off to use templates in this particular game. I'm also curious now how you set up just templates for this game...To just put three different templates with G in a different space would not seem to be very helpful, but if you start involving the rules involving F, V, P and M you wind up going with the possibilities method. Or, is it that you started your templates by looking at one of the other rules instead of the placement of G?

Thanks in advance for your help!

~Steve

[Dave Killoran]

Hey Steve,

Let me jump in here and address what is inside this game that would suggest that possibilities or templates could/should be used. First, as you already know, these two approaches are based on limitations or restrictions within the game scenario and rules. In the Advanced LG course I go into serious detail about the elements that generate limitations within a game (Course link: http://www.powerscore.com/lsat/advanced ... _index.cfm ; as an added bonus, there's a pic of me there ). Second, this game doesn't fit the classic mode of limited games--where there are often one or two "super" rules that indicate obvious limitation--but it does exhibit limitation in a collective sense. Here's how:

1. You have only 6 variables, which, relatively speaking, is a low number of variables for a Linear game. Fewer variables mean fewer total solutions.

2. The three rules collectively address five of the six variables. In other words, there is only one random, and therefore fewer free-floating variables to increase the number of possible solutions (in an ideal world I'd like no randoms, but as we all know the LSAT is not an ideal world ).

3. The first two rules create powerful split-blocks (well, in the case of the first, it's a powerful sequence, but it serves to separate P and M with at least 2 variables). These two blocks alone have a limited number of placement possibilities, and when added together, the number of combinations if further reduced.

4. The variable in the last rule--G--is then restricted to just 3 positions. By itself, this wouldn't be extraordinarily notable, but when combined with the restrictions elsewhere in this game, that chops off more solutions.

What's not to like about the limitations in this game (or, why wouldn't we show templates)?

1. The first rule is open-ended. If this was a straight split-block, there would be only three placement positions, and we would definitely want to use that as a the base for a template attack, at the least. But, the rule uses the words "at least," and that creates six placement options, not three.

2. There is still a random. This is only a minor concern, but a random automatically creates more solutions because the random has no restrictions on placement.

Those two are legitimate concerns, but the first four elements listed above are positive enough that I'd go ahead and attempt it with templates. That leads us to your other question.

In making templates here, I wouldn't choose the first rule as the base--too open-ended for my taste. Nor would I choose the third rule because although it has just three options, in each placement it only occupies 1 of the 6 available spaces (16.6%). Instead, I'd rather fit the first rule and the third rule around the second rule, which has four clearly defined placement options, and at the same time eats up two spaces (33%) of the available positions. And, within those placement options there are severe restrictions. For example, look at what happens if F is first and V is third: G must then be fifth, P and M have no choice but to be placed second and sixth, and J must be fourth, leading to just one solution when F is first. Not every template is that limited, but we now have a better handle on the game.

Please let me know if that helps. Thanks!

[PowerSteve]

Hey Dave,

Thanks for such a thorough response - it is tremendously helpful!

Best,
Steve

[sw51]

Could you please show all the templates you would have created?

[Francis O'Rourke]

Hi Sw,

The initial set up for the templates should rely on the F_V rule. So I would suggest that you say out a few game boards with F_V occupying slots 1_3, then slots 2_4, then 3_5, and finally 4_6. These should serve as the base to the different templates. Let me know if this helps!