LG Game 2 Question 11 Explanation, by LSATHacks
We have two scenarios in this game. Here they are for reference:
Since this is a “order completely determined” question, we should look for an answer which forces us into only one scenario.
A is not a good candidate since it could happen in either scenario.
B is not a good answer, since it puts us in scenario 2, but doesn’t make anything else happen.
C, D and E take more consideration. In timed conditions, you should go with the one that feels more restrictive. But, that kind of intuition only comes with practice, and an understanding of the constraints. So, I’ll try to explain what makes each answer effective or ineffective.
(Though, mainly I solved this by recognizing that all of C, D and E were in scenario 2, and that I could use my diagrams from question 9 to solve things.)
Each of these answers takes place in scenario two. D and E because 1st and 3rd are full in scenario 1. C, because if you place N 4th in scenario 1, there’s no place to put L earlier and also fit O.
So this is like question 9. If you drew some scenarios there, you might recognize that placing N 4th ends up in the following reversible scenario:
That eliminates C: L and O are reversible, so placing N fourth does not completely determine the order. This also helps eliminate D. Not everyone can visualize variables in their head. But you may be able to look at the diagram above, imagine we’re placing O third, and then imagine S and N swapping places. This still obeys all the rules, and there’s no need to draw another diagram. So, placing O third does not completely determine the order (since S and N could swap).
(If you can’t visualize, you can just quickly sketch LSON and LNOS)
That leaves us with E. Normally, placing the random variable doesn’t do much. But here, it forces us into scenario 2. Since MTP are already fixed, I won’t draw them. Here are the first 4 spaces, and who must be placed:
It should be pretty clear that you can’t place L fourth, since N must come after. So, we have to place L 2nd, N 3rd, and O 4th:
(L and O are 2nd and 4th because they must be a space apart from each other.)
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