## PrepTest 79, Game 3, Question 14

### Transcript

Which one of the following cannot be the complete assignment of assistants to Labor? So, we are looking specifically at the labor course, and we want to see who cannot be a complete assignment. So, the correct answer is B, R and Z. So if we just dropped R and Z in L and then closed it off, so nothing else can go there, we have a lot of things to consider here.

So we now still need to place S, T Y and V, so we need to figure out where those are going. Now if we place ST since they have to go together and M, then we're going to force V and Y together in P, but we're also gonna put Y, that's gonna force Y into P, which means Z needs to go along with it. So Y, because we've already placed Z, we know that Y cannot go in P.

So it has to go in the markets course. So if we drop Y there, now we're left with S, T and V. Now, V can't go here because V and Y can't go together, so we know that we have to place V in P. Since we've already placed Y here and taken one of the two available spots, since M can only have two teaching assistants, then S and T have to go in P.

So we're gonna end up with VST which is a total viable arrangement here, but the problem comes in is that we don't have any variables left over to fill this space and markets that must be filled. So M always must have two people assigned to it. When we just put R and Z in L, that prevents that from happening, so this cannot be a possible arrangement.

R and Z does not represent a complete list of those that are assigned to L.

Read full transcriptSo we now still need to place S, T Y and V, so we need to figure out where those are going. Now if we place ST since they have to go together and M, then we're going to force V and Y together in P, but we're also gonna put Y, that's gonna force Y into P, which means Z needs to go along with it. So Y, because we've already placed Z, we know that Y cannot go in P.

So it has to go in the markets course. So if we drop Y there, now we're left with S, T and V. Now, V can't go here because V and Y can't go together, so we know that we have to place V in P. Since we've already placed Y here and taken one of the two available spots, since M can only have two teaching assistants, then S and T have to go in P.

So we're gonna end up with VST which is a total viable arrangement here, but the problem comes in is that we don't have any variables left over to fill this space and markets that must be filled. So M always must have two people assigned to it. When we just put R and Z in L, that prevents that from happening, so this cannot be a possible arrangement.

R and Z does not represent a complete list of those that are assigned to L.