This is an explanation of the second logic game from Section III of LSAT Preptest 73, the September 2014 LSAT.
Five speakers will deliver speeches at a business symposium. The five speakers are: Long, Molina, Xiao, Yoshida, and Zimmerman (L, M, X, Y, Z). Each speaker will give a speech in either the Gold room or the Rose room (G, R). One speech will be delivered in each room at 1 P.M and one speech at 2 P.M. The last speech will be delivered at 3 P.M. in one of the two rooms.
Game Setup
I don’t know how to classify this game. It’s not like any other I’ve seen. It has grouping and linear elements, but frankly, it’s not useful to think of this game in those terms.
The main difficulty on this game is viewing the rules from the right perspective. Particularly the second rule. The second rule says something like this:
Xiao and Yoshida can’t be before Zimmerman.
But actually, once you consider all the rules, this actually mean: Zimmerman must speak at 1pm. Once you figure that out, the game is easy. (Question 13 actually directly tests this deduction.)
I can’t give you a magic bullet for finding this kind of deduction. The game is essentially testing your ability to visualize all five variables, and ask yourself who can go before Z (no one).
Rule 2 says that X and Y can’t be before Z. And rule 1 says that M and L are in the same room.
So only M could go before Z. But if you did put M before Z, then one of X/Y would have to go first in the other room, like this:
This still violates rule 2. So we can conclude that Z has to go at 1pm.
The rest of the setup is just drawing these rules:
Remember, anything that isn’t forbidden is allowed. Any diagram is fine as long as it doesn’t violate these rules.
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Chloe says
I thought the statement “X and Y can’t be before Z” meant it was possible that one of them could occur at the same time as Z just not before? Does this not mean Z could occur at 2pm with X or Y, and the 3pm slot would be filled by the remaining /Y option?