Question about Grouping Games Forum

[notaznguy]

For grouping games, once you make inferences, you can almost instantly eliminate certain answer choices. This is especially help for certain Global questions, such as "Which of the following is an acceptable list of SUBJECT that can be in Group 1?"

However, for certain other questions, where you cannot eliminate most of the answers from inferences and rules, am I right to say the only option you have is to literally do a trial and error test for every single one? This is so time consuming for me. I just wanted to know if this was the norm or not.

If you want to seen an example, see Prep Test 16, Game 1 Question #1 and #6.

In #1, you can easily eliminate answers through inferences. In #6, I had to do trial and error for most answer choices.

[EarlCat]

However, for certain other questions, where you cannot eliminate most of the answers from inferences and rules, am I right to say the only option you have is to literally do a trial and error test for every single one?

No, but I'd probably plug and chug it anyway. The deductions are pretty subtle and take more brain power than I care to spend working through a section, and to sit and think out it is frankly not much better than plugging and chugging.

BUT if you want a non plug-and-chug approach, here it is:

As an overview, you have a game that is fairly open about where elements can go. Of the 8 elements, 5 can go in all three classes, and 1 can go in two classes. What ends up restricting where these elements can go is 1) how many spaces are left, and 2) who's in them (because we have several clues that say so-and-so can't be with so-and-so).

All the answer choice in #6 place two elements in the same place, either in class 1 or class 2. Always start with the options that are most restrictive. Which ones are they? In this case, when you place two elements into class 2, there are still open spaces in all three classes--so its not very restrictive. But when you place two elements in class 1, it gets filled up leaving only 2 classes available. So the answer choices filling up class 1 are the most restrictive. Ignore A and E for now (we'll come back to them if you need them) and deal with B, C, and D. We should already know from our basic deductions that Y must be 1 or 2, and when 1 is filled with other elements, it gets shoved into 2. Unfortunately none of the answer choices say Y must be 2. BUT who does Y restrict? Only W. (It doesn't restrict S because S is already placed.) In choices B and C, W is already placed into 1, which means Y isn't having any effect on it (or anything else). In D, however, W is still waiting to be placed. When Y is forced into 2, W must go to the only other open class, 3, which is exactly what the rest of the answer choice says.

[Storm]

However, for certain other questions, where you cannot eliminate most of the answers from inferences and rules, am I right to say the only option you have is to literally do a trial and error test for every single one?

No, but I'd probably plug and chug it anyway. The deductions are pretty subtle and take more brain power than I care to spend working through a section, and to sit and think out it is frankly not much better than plugging and chugging.

BUT if you want a non plug-and-chug approach, here it is:

As an overview, you have a game that is fairly open about where elements can go. Of the 8 elements, 5 can go in all three classes, and 1 can go in two classes. What ends up restricting where these elements can go is 1) how many spaces are left, and 2) who's in them (because we have several clues that say so-and-so can't be with so-and-so).

All the answer choice in #6 place two elements in the same place, either in class 1 or class 2. Always start with the options that are most restrictive. Which ones are they? In this case, when you place two elements into class 2, there are still open spaces in all three classes--so its not very restrictive. But when you place two elements in class 1, it gets filled up leaving only 2 classes available. So the answer choices filling up class 1 are the most restrictive. Ignore A and E for now (we'll come back to them if you need them) and deal with B, C, and D. We should already know from our basic deductions that Y must be 1 or 2, and when 1 is filled with other elements, it gets shoved into 2. Unfortunately none of the answer choices say Y must be 2. BUT who does Y restrict? Only W. (It doesn't restrict S because S is already placed.) In choices B and C, W is already placed into 1, which means Y isn't having any effect on it (or anything else). In D, however, W is still waiting to be placed. When Y is forced into 2, W must go to the only other open class, 3, which is exactly what the rest of the answer choice says.

EarlCat, are you referring to specific game from an old PT?

[JazzOne]

I agree with Earlcat. I usually prefer to plug and chug even if I think there are subtle inferences I could make with more time and effort. However, I do have a shortcut that I often share with my students. Suppose you get to a general (or global) question and you cannot eliminate any answers through obvious deductions. So, you plug in answer A, but it proves to be incorrect, so you move on to answer B. Here's my tip: Don't start your analysis for answer B from scratch. Instead, use your analysis from answer A to guide your analysis of B. Whatever the rationale was for eliminating A, see if the same or similar rationale applies to eliminate B. I'm often surprised by how many answers can be eliminated for virtually the same reason.

Also, for global questions, I sometimes use the idea of equivalent elements. For instance, suppose you eliminate two answers and the remaining answer choices are element x, element y, or element z. Furthermore, there is a rule dealing with element x, but elements y and z are not mentioned in any of the rules. Without even knowing the question, I can conclude that the answer is element x. The reason is that elements y and z are entirely indistinguishable. If y was a satisfactory answer, then z would be satisfactory as well. Since there cannot be two correct answers, they must both be wrong.

[bp shinners]

I'm going to be the dissenting opinion here and say that you can usually make some relatively simple deductions up front that will prevent you from having to do a lot of plug and chugging in grouping games.

At the very least, you can usually break a grouping game into 2-3 scenarios which will let you answer most questions quickly without having to plug and chug through everything.

However, I do usually suggest to my students that they look at the global/absolute questions if they can't make any deductions. If you're really stuck and you plug and chug your way through one of them, it usually gives you a deduction that you can apply to all of the other questions.

[EarlCat]

EarlCat, are you referring to specific game from an old PT?

Prep Test 16, Game 1 Question #6.