LSAT 80, Game 3 Setup, Oil and Watercolor Paintings, LSATHacks

Game Setup

Time on first attempt: 8:30

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This is a grouping game with two elements: a painter, and a type of painting. It’s also a rare type of game where a lot can be determined in advance. These used to be extremely common on logic games from preptest 50 or earlier. 

Games where you can determine a lot upfront have become quite uncommon on recent tests. However, their occasional presence shows that mastering the old skills is still valuable. It can flip a hard game into an easy one. Once you master the basics of newer games, it is worthwhile to work on some “classic” LSATs in order to build a wide skillset.

You can draw the game like this:

I’ve drawn rule 5 directly on the diagram: Isaac’s oil is in the lower position of wall 4.

I don’t bother numbering the walls. It’s easy to see which is upper/lower, and which is wall 1, wall 3, etc.

I use the space under the slot to mark the type of painting, and the space above for the painter. This makes for a cleaner, more efficient diagram, which is nonetheless still clear.

The first two rules I simply memorized: 

1. You can’t put only watercolors on a wall, and 
2. You can’t put both of student’s oil and watercolor paintings on the same wall.

It’s worth thinking about the first rule. We know there are four watercolors, and four oil paintings. The first rule says you can’t fill a wall with watercolors. 

What does that meant for the distribution of the painting types? Think about this a moment if you haven’t, and try drawing it.

Done? Let’s try putting two oils on wall one. Remember, we can’t place two watercolors on the same wall, so avoid that as long as you can: 

Oops. No matter how you try to work it, you end up with two watercolors on wall 4, which doesn’t work. 

It turns out that each wall must have one watercolor and one oil painting. There’s no other way to obey rule 1.

So we can say, for example, that the upper painting on wall four is a watercolor:

Rule 3 says that Franz and Isaac don’t share walls. Here’s how to draw it. The curved line indicates they’re reversible:

You should always see if new rules can be combined with the diagram. Since F and I can’t go together, that means F can’t go above I on the fourth wall. You should draw that as a not rule:

Next, rule 4 says that Gw is above Fo:

You should also draw that as a not rule on wall 4. Upper wall 4 is a watercolor, but it can’t be Gw, because the bottom of wall 4 is Isaac instead of F. This greatly restricts wall 4’s watercolor:

Whenever not rules start accumulating, you should think who can go there. Only I and H are left. And I can’t go, because they have the bottom position (rule 2, students can’t fill a whole wall). 

So, wall 4’s upper section must be H’s watercolor!

This deduction greatly restricts the game, because we know that one other wall is Gw above Fo (rule 4). That leaves only two “open” walls left. It’s worth thinking who can go there:

• Go, Ho, Iw, Fw

That’s really quite limited, especially since you have to match the watercolors with the oils. So, making that deduction about H in wall 4 really narrows the game.

Also, one key insight is that for these four remaining variables, upper/lower doesn’t really matter unless a question specifies it. If you look at the answers for question 9, 13, 14 and 16, they talk exclusively about walls – they don’t mention upper or lower. And more than half the answers on questions 15 and 18 also don’t mention upper/lower.

So, when sketching scenarios, if a question tells you to put H’s O on wall 2, just stick them on that wall, and don’t worry whether you place them upper or lower. The only important thing is who you match them with, not whether they’re up or down. 

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