LSAT 66, Game 4 Setup, Piano Solos, LSATHacks

This is an explanation of the fourth logic game from Section III of LSAT Preptest 66, the June 2012 LSAT.

Two pianists, Wayne and Zara (W, Z) will perform five solos in a recital. Each piece will either be modern or traditional (M, T).

Game Setup

This is a game where you can solve almost everything before starting. That’s rare on the modern LSAT.

To do this, you must split the game into two scenarios. The third rule nearly forces you to make such a split.

Whenever a rule gives you two options, draw both of them. It lets you make extra deductions, and visualize the game more easily. This is a hidden feature of LSAT logic games.

But I’m getting ahead of myself. Let’s start with the first rule. The third solo is traditional:

You could make two rows to put both the performer and the type of music they play. I prefer to just put the type below the slots. It makes a smaller, simpler diagram which is easier to recopy.

Let’s come back to the second rule in a minute. All we can do with it at the moment is try to draw it, which isn’t very useful, since it’s a non-standard rule.

It’s perfectly ok to skip rules and come back later. I read everything before drawing precisely so that I can see which rules are simplest to draw first.

Rule 3 lets us make two scenarios.One where W performs a traditional piece, and one where Z performs a modern piece:

Now we can add the second rule. It says there is one and only one group of two consecutive T’s. You can’t put more than two T’s together, and it can only happen once.

In the first scenario, that has already happened. That means 2 and 5 must both be M:

In the second scenario, 2 must be T, and 1 must be M. It’s the only way to put two T’s together, but no more than two T’s:

Here’s how I drew the fourth rule, that 2 and 5 must have different soloists:

Lastly, W must perform a modern piece before the first traditional piece. In the first diagram, that means that the first piece is modern, and W goes first or second:

I made up this way of showing W can be 1 or 2. It’s not a common rule. If you come across an uncommon rule, feel free to improvise.

In the second diagram, W must go first:

There is very little uncertainty in this game. All the rules are drawn directly on the diagram.

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