Tricky Ordering Rules

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One of the keys to unlocking the LSAT Logic Games section is to represent the rules as visually and completely as possible. Most of the time, doing so is relatively straightforward, but there are some rules that are trickier to understand and visualize. Today, we’ll talk about some tricky rules you might see in Ordering logic games and how to approach them to squeeze every last bit of information out of them.

“A is before B or after C, but not both”

When encountering this rule for the first time, a lot of students’ instinct is to write out the first part normally, and then write the words “but not both” afterwards. However, writing out the rule that way doesn’t let you see its full impact. Instead, think about what it really means: When A is before B, it cannot be after C, so A is before both B and C. Likewise, when A is after C, it can’t be before B – meaning it’s gonna be after B as well. So in that case, A is after both B and C.

So now we have two options: one in which A is before B and C, and one in which it’s after those guys. Your “make scenarios” internal alarm should be a-ringin’! You’ll create two scenarios, one for each possibility, and incorporate the other rules into those scenarios as well.

“Susan’s mud-wrestling match is three days after Tracy’s”

This rule is easy to parse, but can be tricky when it comes to actually writing it out. Susan is a set number of days after Tracy, so you’ll represent the rule with a block; I find it easiest to actually count out the days when writing (e.g. “ok, self, you’ve got Tracy, then there’s one day, two days, and Susan is on the third day.”).

“If Marquitta is before Chuck, then Biff is before Trevor”

This rule is easy enough to understand, but the contrapositive can throw people off a little. It’s as simple as flipping the order of the pairs, so the contrapositive in this case would be “If Trevor is before Biff, then Chuck is before Marquitta.” If you find yourself in a situation where, for instance, it’s not actually possible for Chuck to be before Marquitta, then you’d know that Trevor can’t be before Biff either (because the contrapositive would be forcing you to do something that isn’t possible).

Ordering games are often relatively simple, and the ones that are tricky are usually tricky because they have some weird rules, like the ones discussed here. As long as you make sure you’re always getting as much information from the rule as possible, you’ll be in great shape!

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