Q15

[JackelineZ38]

Hello! Can someone help me figure out how to tackle this question? Is there a key inference I likely missed in the diagram?

Thanks!

[Laura Damone]

Hi!

This is a basic grouping game with three groups and a chunk. So, when I take my big pause, I'm asking myself "would it be worth framing around the placement of the chunk?" Since the chunk filling G would trigger the contrapositive of rule 1, and the chunk filling H would trigger the contrapositive of rule 2, it seems likely to me that the frames will be fruitful, so I go for it. In the diagram below, read the left group as group F, the middle as group G, and the right as group H:

R ___ ___
T ___ ___

___ R ___
___ T ___

___ ___ R
___ ___ T



When RT is in H, W can't go in F. So W goes in G. S can't be with W, so it goes in F. S in F means X in G. So the last slot in F must be filled by whichever element goes twice.

When RT is in G, S can't go in F. So S goes in H. W can't be with S, so it goes in F. W in F means X in H. So the last slot in X must again be filled by whichever element goes twice.

When RT is in F, we don't trigger either conditional. But we know we have to separate S and W so they go in a cloud over G and H. That leaves X and whichever element goes twice in another cloud over G and H.

The frames make 15 easy. R and X can never be together.

Whenever you have a basic grouping game with a chunk, consider trying the chunk in each group. It can be a very effective framing technique!

Hope this helps!