October 2013 LSAT Section 3 Question 7
Which one of the following, if substituted for the constraint that Wellspring and Zircon each perform in an earlier s...

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Ravi on June 3, 2019
@msaber,Happy to help. Let's look at (E) and (A).
In looking at our original rules, we have
V - Z - X and W - X
U must be in 4/5/6
U having to be in 4/5/6 means that V must be in 1/2/3 because V has to
come before Z and X and if V were in 4, then we wouldn't have enough
room for Z, X, and U.
V must be in 1/2/3
Y must be in 1/2/3
Y having to be in 1/2/3 means that X has to go in 5/6 because V, Z,
and W come before it and if X were in 4, then we wouldn't have enough
room for V, Z, W, and Y.
X 5/6
The question tells us we are subbing a new rule for the rule that W
and Z are before X.
(E) says X performs in either slot 5 or 6.
The problem with (E) is that if we substituted this rule in, we could
have W and X swapping places in 5 and 6, whereas in the old world W
had to come before X.
With (E), we could have a game board that showed
Y V Z U X W
This board wouldn't be possible with our original rules, so (E) is out.
(A) says only U can perform in a later slot than X.
This means V, Z, W, and Y have to go before X and U is the only piece
that can go after.
This restores the W before X from our original rules. It also restores
Z going before X. V was already before X, so that stays the same. And
Y before X? Yes, that was true in the original rules because we know
that Y had to go in 1/2/3 and X was in 5/6, so (A) is a perfect rule
substitution. In our original rules, U, having the ability to go in
4/5/6 was the only piece that could go after X in 5/6.
Hope this helps. Let us know if you have any more questions!