Q22

[MitchellL341]

Would someone post an explanation, please? Thank you!

[Misti Duvall]

Sure! If G only presents in group J, that means R is also in group J and G is not in group M or Group S. So the only options for groups M and S are R in both, W in both, or R and W in both.

R in both is fine, and would be:

M: R
J: G R W
S: R

That's R in all three, which is answer choice C. Since it's a could be true, we can stop there and don't need to try out the other two options.

However, I'll do that here in case anyone else did.

W in both is also fine:

M: W
J: G R
S: W

R and W in both is a problem, though, because of the second rule:

M: R W
J: G R
S: R W (can't work, because if R is here, W cannot be)

[JorgeL203]

Sure! If G only presents in group J, that means R is also in group J and G is not in group M or Group S. So the only options for groups M and S are R in both, W in both, or R and W in both.

R in both is fine, and would be:

M: R
J: G R W
S: R

That's R in all three, which is answer choice C. Since it's a could be true, we can stop there and don't need to try out the other two options.

However, I'll do that here in case anyone else did.

W in both is also fine:

M: W
J: G R
S: W

R and W in both is a problem, though, because of the second rule:

M: R W
J: G R
S: R W (can't work, because if R is here, W cannot be)

Hello! I struggled with this question because I thought there were three frames:

Like you said, R in both M and S:
M: R
J: G R W
S: R

Like you said, W in both M and S:
M: W
J: G R
S: W

But ALSO, W in both M and S AND also in J:
M: W
J: G R W
S: W

How did you know to not worry about the third frame during your prephase? I want to get better at doing only what is needed to answer an LG question, to avoid wasting time.

Thank you!

[Laura Damone]

Hi there! You're not wrong: that's an option, too. When I did my prephrase, Like Misti, I filled in GR in J, then considered my options for M + S. G can't be in either, so we've got to have either R or W, but not both. I represented that like so:


R      /           /
G    R/W --> RW
 J       M         S


Because the upper rows are slashed out in M and S, there's only one more slot to consider, which is the top row of J. Looks like W could go there, or not: either is fine. If I want to make note of this kind of "if anyone fills this slot, it's X" type of inference, I'll put the element up there in parentheses.

This represents all the possibilities of what could be true without framing, which in this case is more efficient. That said, if you wanted to frame out R R vs W W in M/S, you could do that with only two frames and the W in parentheses without taking much time at all.

Hope this helps!