This is an explanation of the fourth logic game from Section III of LSAT preptest 32, the October 2000 LSAT.
A pet shop will feature kittens and puppies for seven consecutive days (1, 2, 3, 4, 5, 6, 7). One breed will be featured each day. There are three breeds of kitten – Himalayan, Manx, and Siamese (H, M, S) – and three breeds of puppy – Greyhound, Newfoundland, and Rottweiler (G, N, R).
I haven’t seen another game quite like this. I suppose it’s a linear game, but I don’t feel that classification helps here.
This game requires you to know the rules. Know them cold. If you can learn to keep 3-4 facts in your head for eight minutes, forty-five seconds, you’ll do much better on logic games.
The most useful thing here is to draw rules underneath your diagram that show which variables
can’t go in certain spots.
It’s easiest to draw everything horizontally. If you look at the first question, you’ll see that the LSAT has represented the kittens horizontally.
G goes on day 1. Rule 2 says no breed can go beside itself, so G can’t go on day 2. And we know from rule 3 that G can’t go on day 7. (The same variable can’t go on days 1-7)
Rule 5 tells us that R also can’t go on day 7. So since both G and R can’t go on day 7, N must go there.
N can’t go on day six, since no breed can go twice in a row.
I also added rule four: H can’t be featured on day 1.
The one rule you absolutely must remember without putting it on your diagram is that H and R can’t go together. You could draw it like this:
But it’s most effective simply to memorize this rule.
There are several possibilities for how to place the three H’s, so it’s not worth your while to draw scenarios. Local rules for individual questions will limit where H can go, and you can draw H on your diagram then.
The rules are mostly for puppies. H is the only type of kitten mentioned in the rules.
Here’s a list of rules to remember:
- The first and last breeds are different
- A breed can’t go twice in a row
- H can’t go with R
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