LSAT 79, Logic Game 2, Question 9, LSATHacks

This question asks who can be third. To answer this question, you should look at third and think about what we already know about it:

We know two things:

1. M must be third.
2. L must go with M or K, but not both of them.

That means, therefore, that K can’t go third. So, this question was already solved from the setup.
D is CORRECT.

Sometimes, of course, you won’t make that deduction in the setup. Here’s another way to solve it: think about whether placing a variable third makes it easier or harder to fulfill the rules.

For example, O and P can’t go first. So, placing them third fulfills that rule and therefore makes it easier to solve the game. Therefore, it is likely possible that O and P can go third. 

Rule 1 places M third, so that also can’t be the answer. And we know from past questions that L can go third (since L goes with either M or L).

That leaves only J and K as possible answers. And J and K are identical, except that K also has the additional rule that it might have to go with L. This makes J easier to place than K, and therefore J is unlikely to be the answer.

So this process also leads us to K. This “easier/harder” framework comes in handy quite a bit in choosing between answers on “could be true” and “cannot be true” questions.

---