This is an explanation of the second logic game from Section II of LSAT Preptest 65, the December 2011 LSAT.
Six consecutive presentations on six different subjects will be given at an open house. Jiang will present needlework and origami (N, O), Kudrow will present pottery, stenciling and textile making (P, S, T) and Lanning will present woodworking (W). You need to use the rules to determine what order they can present in.
This is a linear game. It’s less complicated than it looks.
My central theory for logic games is that success depends on figuring out how to make a complicated situation less complex.
Our brains can’t handle more than about 7 facts at the same time, and the more facts we have to keep track of, the worse we do. So every rule you simplify improves your effectiveness.
For instance, the game lists three teachers, so you might think they’re an important part of the game.
They aren’t. Instead, the six presentations are all you have to worry about.
So you could draw this list of teachers, but I don’t find it helpful.
Exactly one question asked about a teacher (question 9), and you can just look back to the rules to see what classes that teacher teaches.
The first rule does involve a teacher, but we can turn this into a rule about the presentation.
The rule says K can’t give two presentations in a row. What this really means is that P, S and T can’t be beside each other. Here’s how I drew it:
If you studied Powerscore, you’ll have seen this diagram, and you’ll recognize that I’m using it the wrong way. Technically, in the Powerscore system, this diagram means that PST can’t form a group of three.
Who cares? I’m giving the diagram a new meaning for this game. I know the context of the game. Only the first rule keeps people apart. So I read my diagram as meaning you can’t have PS, SP, PT, TS, etc.
The traditional way to draw this rule would be like this:
I personally find this diagram hard to read quickly. On logic games I care most of all about being right AND fast.
You should be copying this diagram on the page as you follow along with these explanations. Use whichever method makes more sense to you.
This game only has six spaces. That’s pretty restrictive. Here’s the setup:
I’ve added in the deductions from the first and second rule.
We’ve drawn all the rules. But before starting a game, you should always see if a logic game has a particularly restricted point. Here, P, S and T are very restricted. Especially S and T.
You always have to space PST apart from each other. You’ll get diagrams that look like this. The X’s represent PST in any order:
There are too many possibilities to bother drawing each one, but you should be aware that whenever you place one of PST, the others may be forced into specific spots.
Especially if there is no PST in spot 1 or 6. PST take up 5 spaces at minimum. The first diagram with the X’s is an example of this.
I said S and T are particularly restricted. This is because they are affected by other rules. Their order is S – O and T – W.
So out of PST, P tends to have to go last. If P goes before S and T, there often isn’t enough space to put S – O and T – W. A couple of questions test this deduction.
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