Setup and Rule Diagrams

[Administrator]

Setup and Rule Diagram Explanation

This is a Defined-Moving, Balanced, Numerical Distributions Grouping game.

The game requires us to assign six variables (teaching assistants) to three different groups (courses). Since each variable is used exactly once, the game is Balanced. However, only one of the groups (Markets) requires a specific number of variables (2), making this game Defined-Moving.

With all the rules represented, your initial setup should look like this:

PT79_Game_#3_setup_diagram 1.png

A thorough analysis of this game requires understanding the Numerical Distributions that govern the assignment of variables to groups. Since there must be exactly two variables assigned to Markets, there are three fixed distributions at play: 2-2-2, 1-2-3, and 3-2-1. Fixed distributions usually, though not always, present an opportunity to undertake a templates-based approach, where each distribution provides the basis for a different template. Unfortunately, in this game, the rules do not seem powerful enough to justify such an approach.

In theory, a templates-based approach is also possible by tracing the placement of the ST block in each group. However, the block is not exclusive, i.e. it allows for the inclusion of other variables in the same group as S and T. Furthermore, none of the other variables are directly restricted by the placement of the ST block. A templates approach based on the placement of the ST block is a risky proposition, and is probably not worth the investment of time.

A better course of action would be to analyze the last rule, which is complicated enough to warrant a closer look:

Since Y and Z must both be assigned to P if either one of them is, we are looking at a bi-conditional statement: if Y is assigned to P, then Z must also be assigned to P. Inversely, if Z is assigned to P, then Y must follow suit. By the contrapositive, if either Y or Z is not assigned to P, the other variable cannot be assigned to P either:

PT79_Game_#3_setup_diagram 2.png

Essentially, the rule entails two situations that are both mutually exclusive and collectively exhaustive: either Y and Z are both assigned to P, or else neither Y nor Z is assigned to P. We can represent the implication of this rule using two possible outcomes, as shown below:

PT79_Game_#3_setup_diagram 3.png

Although neither scenario is sufficiently restrictive to place all, or even most, of the variables (and thus a strictly-templates attack is unwise), an early consideration of this duality may obviate to some degree the need to apply the complex language of the last rule to each and every question. Effectively the game is “split,” and the full implication of the last rule can be more clearly seen with this quick examination.

Observant test takers will also notice that Possibility 1 is the more restrictive of the two, since the ST block cannot be assigned to P (because the maximum number of variables per group is 3). Therefore, in that option the ST block must be assigned to either L or M, and this new split is also worth a look:

PT79_Game_#3_setup_diagram 4.png

Note that in 1B, V must be assigned to L, because Y and V cannot be assigned to the same group as each other (third rule), and M is full. Unfortunately, as noted, Possibility 2 is not nearly as restricted, because Y and Z can be assigned to either of the two remaining groups, whether separately or together. Thus it remains too open-ended to merit further analysis, and can be left alone.

[tanushreebansal]

Is it worth identifying the templates in this game? I didn't use that strategy while I was taking the test because I was short on time. But when I went back to review, I found 14 templates in total and found they were helpful in answering question 15. What would Powerscore do?

[James Finch]

Hi Tanushree,

Having just gone through the game, the short answer would be that yes, Identifying the Templates is worth it in this case, but that Identifying the Possibilities, all of the possible variable positions, is not. I believe you are referring to Identifying the Possibilities when you refer to the 14 possible templates for this game.

My personal general rule for Identifying the Possibilities is that more than 4 possibilities means I would spend more time creating the templates than they would save me in answering the questions, although there are certainly exceptions that come up from time to time, like Game 3 ("Stones/Mulch") from the 2010 LSAT.

This game is based around identifying the possible numerical distributions, but since no single variable ("teaching assistant") or block of variables is forced into a specific group ("course" in this case), I stopped at creating three general templates to reflect both possible 3-1-1 distributions and the 2-2-2 distribution, and then used those templates to answer the questions, not bothering to even try and Identify the Possibilities. Instead, I used the technique of Hurdling the Uncertainty to attack the answer choices directly.

That the correct answers for the first three global questions, 13-15, are answer choices (A), (B) and (A), respectively, leads me to believe that this was the approach intended by the test makers themselves. If you have ample time, however, Identifying the Possibilities does make it possible to answer the questions very quickly.

On question 15, the answer choices create a third power block to use to test answer choice (A). Alternatively, one could immediately eliminate answer choices (B) and (C) because they would force Markets to have both the S-T block and and additional variable, overloading that group, then eliminate (D) for doing the same, and (E) as well because of the Zp Yp block and Y V not law, leaving only (A) as a possible Contender.

Hope this helps!

[edacyu]

Hi there, reopening this thread if you don't mind.

Generally speaking then, in Logic Games questions, I've found myself going through all the possibilities and to ensure that I've arrived at the right answer choice even after finding one that works (so, as you indicated in this game, (A) (B) and (A) for the first three.

Would you suggest not necessarily going through each one after landing at a correct answer to save time in a game setup like this (where Identifying the Possibilities upfront takes up too much time)?

Thanks so much!

[Alex Bodaken]

edacyu,

Of course we don't mind at all, and thanks for the question! This is going to be an unsatisfying answer, but...it depends. Meaning, if you have time, it's always great to go through all of the alternate possibilities to make sure you can eliminate them; but if you are short on time and are confident you have the right answer, the more optimal strategy would be to move on to ensure that you have time to spend on additional questions. Which of these approaches you choose will depend primarily on how many questions you have left in the section: if you have 2 questions left and 10 minutes, yeah, go back through and eliminate wrong answer choices; if you have 12 questions and 7 minutes, I'd trust my answer and move on. I know that's not a hard and fast rule, but hopefully it gives some guidance on how to approach these.

Hope that helps!
Alex

[lsatdaynnight]

Hi,

Can you please clarify what you mean by "that the correct answers for the first three global questions, 13-15, are answer choices (A), (B) and (A) makes it clear the test takers intended it to be a hurdling the uncertainty technique"?

Thank you!

[lsatdaynnight]

Hi,

I am having a difficult time understanding the biconditional rule. Would it be possible to please explain it in further detail?

I am thinking about it as below. Can you please let me know if the thought process below is accurate:?

First Rule: If O/2 -> J and K are together
Contrapositive: If J and K not together -> O not in 2

The second part of the rule:

Second Rule: If O is not in 2 then J and K are not together
Contrapositive: If J and K are together -> O/2

We know it is a biconditional because the first rule [If O/2 -> J and K are together] and contrapositive of second rule [If J and K are together -> O/2] is biconditional.

Similarly, the second rule [If O is not in 2 then J and K are not together ] and the contrapositive of the first rule [If J and K not together -> O not in 2] is biconditional.

Is the above method of thinking correct? Thank you!

[Adam Tyson]

That looks correct to me, lsatdaynight! The use of "otherwise" in the rule is the clue that this will set up a biconditional relationship. "If A, then B, otherwise not" does exactly the same thing as "A if and only if B" and "if A, then B, and vice versa." There are several ways to create that relationship!

I think you probably meant to post this question under a different thread, though, as the rule you are referring to is from game 2, not game 3 from this test. You can find more about that game at this thread: viewtopic.php?f=1197&t=15241

[LawSchoolDream]

This game was particularly cumbersome for me. I got all correct but it took quiet a bit time (22 min). Any way to do it faster? I was rediagrramming for almost every question because of the rules and blocks

[Jeff Wren]

Hi LawSchoolDream,

I would consider this game above average in difficulty, and it does require a fair amount of diagramming to solve the questions.

That being said, the game can be solved in less than 22 minutes with the proper setup and the proper approach to solving the questions. Generally, you won't want to diagram out each answer choice unless unavoidable. In this game, doing the local questions (16 and 17) first may be a helpful strategy as it provides hypothetical solutions that may be useful to solving the global questions.

This is a special type of grouping game that we classify as "Moving," meaning that the variables can move across the groups. These games generally have several numerical distributions, which often overlap with the strategy of Identifying the Templates.

Be sure to thoroughly review our setup and discussions for the questions.

Finally, depending on where you are in your logic games studies, you aren't necessarily expected to have your timing down yet. Speed is the last thing that comes after a ton of practice, so if you're still just learning how to do the games, then don't worry so much about timing at first.