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# Grouping setup | "Completely determines" | Worked example

Watch a demonstration of one way to approach a "completely determines" question on a grouping setup on the LSAT analytical reasoning section. Created by Annie Hollister.

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• I am a little confused on Answer Choice D in this question. Here is my diagram that I used.

Initial
Dress 1: Red, White, Orange
Dress 2: Indigo, Yellow, Unknown
Dress 3: Unknown

If you implement answer choice D:
Dress 1: Red, White, Orange
Dress 2: Indigo, Yellow, Unknown
Dress 3: White, Indigo, Yellow

My reasoning for Choice D is this: If exactly 1 dress has Indigo and White, then it must also have Yellow. This can be dress three for example. Just as the narrator of the video assumed white can added in dress 2, that did not lead anywhere and left dress 3 empty. Therefore, the narrator crossed it out. However, why can't you assume that the Indigo and White combination is in Dress 3?

If you look at it that way, then you see that Yellow has to be added to Dress 3, and then since Green hasn't been used yet, it would have to be in Dress 2 with Indigo and Yellow, solving the colors in each dress completely. This rationale contradicts choice A as well.
• The question asks for which answer "completely determines" the colors of each of the three costumes. The problem with D is that although you can create a way for it to work as you have, there is also another way:

1: Red, White, Orange
2: Indigo, Yellow, White
3: Green, Orange, White

Because there is more than one possible scenario, this means that it doesn't completely predict the rest of the costumes whereas for A), there is only one set up that can be laid out.
• I chose (E)
I am confused how it was not selected.

The diagram drawn shows that there is only exactly one costume that has both orange and white, which goes with E.

Answer (A) can't be true because it is not true that white is in all three, white could bd in just two. But answer (E) is a definitely if True

Could you please explain this better for me?
Thank you
(1 vote)