LG Game 2 Question 9 Explanation, by LSATHacks
This question places Z 7th. This restricts T _ _ W. Normally, they can go in 2/5, 3/6 or 4/7. This question eliminates that last possibility. Since there are only two possibilities, we can instead draw scenarios for both: one with T in 2, and one with T in 3:
The first scenario is quite restricted. We need to put XU together. The only place to do that is between T and W:
Only R and S are left to place. Rule 3 says SZ can’t go together, so S has to go in slot 1, leaving R for slot 6:
The next diagram is more open ended. XU can either go 1st and 2nd (in either order) or 4th and 5th (as XU).
RS will fill the other two slots, in either order.
(As I said above, XU must be in that order in slots 4/5, but could be UX in slots 1/2. The restriction in 4/5 is to keep X away from W)
Looking through the answers you can see D is CORRECT. It’s possible in the second scenario. (Remember, XU are reversible in slots 1 and 2, when away from W.)
None of the other scenarios are possible in either diagram.
You could also look at one of the completed diagrams from Q7, notice that Z could be placed in position 7 in that diagram, and go on from there. X and U are interchangeable in that diagram, so U could go first. I’m actually kinda proud of how I got that–I’m usually terrible at logic games. I learnt that variable-switching technique from you!