Q14

[noah]

14. I knocked off everything that had T in it, since anything linking with H -- and there needs to be at least one -- will also have to link with T. In short, we can't have T and some other city having an exclusive relationship since we know that H would be connected with someone else, and since any city that connects with H must connect with T, there's a problem! That eliminates (B), (C) and (E).

Between (A) and (D), you could try them both out -- not too time-consuming an effort -- or consider which one seems more likely to cause a problem. (D) is problematic because it leaves H, M and T alone to connect with each other. H and T can't connect to each other, leaving it up to M to do all the "work" of connecting to H and T, but M can only connect with one city.

[indyyork]

14. I knocked off everything that had T in it, since anything linking with H -- and there needs to be at least one -- will also have to link with T. That eliminates (B), (C) and (D).

I know you mean to eliminate B, C & E since they have T!

[robowarren]

Hi,

Would you mind explaining this a bit more? Why did you get rid of any answer choices with T right from the start?

[timmydoeslsat]

So we know that with a could be true question, four of the answers will be "must be false" and one will be could be true.

Let us go through the five answer choices.

A) I would actually try this out if I were taking the test. It would not be that long to do and I do not see any rules restricting this.


With the rules as they are, we know that H can only connect with P and V. At least one of them must be present in H.

So let us plug in what this answer choice states.

H
M: P XX
P: M XX
T
V


I used the XX denotation to show that the row is full and nothing can be added to it. We now can infer that H must be connected to V. It cannot connect to M and P because they are full and it cannot connect to T because of our rules. So we can do that:

H: V XX
M: P XX
P: M XX
T: V
V: H T

We also know that H is full now with the placement of V there. Since V went to H, it must also be present in T because of our rules. So I showed that in the V row, that V went to H and T.

This right now is a valid hypothetical and we can stop here. However, you could continue to add to this hypothetical. We see that T and V could go together.


We will also go through the thought process if it were the case that you saw this answer choice during the test and wanted to not try it out at first because you wanted to eliminate answers first.

B) M and T are connected to each other and no other city. Is this possible?

We must remember that each city is used. So we know that H is used. Well if H is used, we know that it will send that same place to T. So according to this answer choice, M and T are only connected to one another:

H:
M: T XX
P:
T: M XX
V:

So if we were to figure out who could go to H, it is either P or V (or both of course). But think what would happen if we put either of those variables in H. We could not place it in T according to this answer choice, and this is not possible.

This same phenomenon is occurring in answer choices C and E as well.

D) This answer choice is precluding H from going with anyone also! Remember H cannot go with M or T. The T rule was explicit, but we inferred M could not go with H because M can only go in one city. If M went to H, it would also have to go to T.

So we know that H has to have at least one of P and V, and this answer choice precludes it.

[noah]

14. I knocked off everything that had T in it, since anything linking with H -- and there needs to be at least one -- will also have to link with T. That eliminates (B), (C) and (D).

I know you mean to eliminate B, C & E since they have T!

Thanks, I'll correct that typo!

[noah]

Hi,

Would you mind explaining this a bit more? Why did you get rid of any answer choices with T right from the start?

In short, we can't have T and some other city having an exclusive relationship since we know that H would be connected with someone else (every city must), and since any city that connects with H must connect with T, there's a problem!

That make sense?