LSAT 21, Game 3 Setup, Witness Interview, LSATHacks

Game Setup

This game has elements of sequencing. It also has a big wild card:  two full days will be taken up by the hostile witnesses.

We have the six days of the week, from Monday through Saturday. Each day is separated into morning and afternoon. That’s twelve total spaces. We have six non-hostile witnesses to interview and four hostile witnesses. So we are always going to have ten spaces full and two spaces empty.

One thing that often confuses people from the opening paragraph is the part that says the only witnesses that will be interviewed simultaneously are Q and R.

That tells us two things. Most people get that none of the other witnesses are interviewed at together

But it also means that Q and R are always interviewed at the same time. So what I said earlier wasn’t quite true. We don’t always have ten spaces full, we always have nine full, since Q and R take just one space.

The first rule just tells us that X is on Thursday morning. This is a big dividing facto. Hostile witnesses can’t go on Thursday because X is already there.

Here’s how we draw the basic diagram without any other rules.

Next, Q is interviewed before X. This really means that Q and R are interviewed before X.

U is interviewed before R, meaning U is interviewed before QR.

And lastly, Z is after X. Y is before Z. It looks like this:

The game looks pretty open ended. You should figure out what the most limiting factor is. The hostile witnesses take up two full days: let’s try putting them in Friday and Saturday and see what happens.

We know Z has to go after X. The only space left after X is on Thursday afternoon. So that’s where we have to put Z. Then U, QR and Y are all before X. We don’t know which order so we can just draw it like this:

That’s one scenario.

Next, we should see what happens if the non-hostile witnesses are interviewed before X. There are two scenarios and they look pretty similar.

The hostile witnesses take up four of the six spaces before X. U and QR both have to go before X , so U and QR must fill the other two spaces.

If you put the hostile witnesses on Monday and Tuesday, U and QR go on Wednesday. If you put the hostile witnesses on Tuesday and Wednesday then U and QR go on Monday.

Either way, that forces Y to go after X. Z will always go after X and Y: that is one of the rules. So these two scenarios look like this:

One important deduction is that in these scenarios, hostile witnesses are always interviewed on Tuesday. So if hostile witnesses go before X, they must always be on Tuesday.

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