PTB.S2.G2 - an apartment building has five floors

cinthya528581

In the third rule, it says that if y is not in the park if either L or O is in the park, but then on the explanation, the sub game boards, he says that Y can be in or can be out if either L or O are out..., what am I missing? I thought if either one of them was out, then y had to be out too.
Please help!
https://7sage.com/lsat_explanations/lsat-b-section-2-game-2/

BinghamtonDave

The third rule reads that in the absence of Y then we better see L or O but not both. In other words:
Y----> L or O both

Lets tinker with this rule a bit. Lets see what kind of situations would logically arise given this rule specifically.
Lets start with the absence of Y also known as a fulfillment of the sufficient condition. What situations could the absences of Y lead to?
1.Y----->L/O In English: Y out, L in, O out.
2.Y---->O/L In English: Y out, O in, L out.
These are the only 2 situations that can come out of an absence of Y. Anything else would be a violation of our stated condition.

In our first series of possible events coming from that rule we_** fulfill the sufficient condition_. Now, lets fail that sufficient condition. Y is in=The rule falls apart**. Think about it like this: If the Patriots win the super bowl next weekend then Tom Brady is the single greatest player to ever play football. If the Patriots don't win, does that exclude Tom Brady from being the greatest ever? No. He could fulfill a different set of sufficient conditions that get him to that status.

So we fail the sufficient condition- which is a bit difficult because the sufficient condition for rule three is presented to us in the negative form, nonetheless lets fail that condition:
Y is in. So that gives rise to these possibilities:
Y is in so L is in and O
Y is in so O is in and L
Y is in so both L and O are in
Y is in so both L and O

Given the third rule by itself those are the possibilities. Now lets take a look at question #10 for an example of why I love In and Out games! Tinker with these rules, it pays dividends. First, lets lay out our game pieces here:
F L M O P S Y

10 tells us that F is out. So lets cross it off our list:
F L M O P S Y
Lets now take our 4th rule:, contrapose back and we know that L and O must be in.

F L M O P S Y

Now, given our deconstruction of rule 3, the only situation where both L and O are allowed in, is the situation where Y is also in.

F L M O P S Y

Lets pause there: 2 steps away from where the question stem left us. If Y is in, then M must be out.

F L M O P S Y

Answer choice (A): we linked three rules, made four steps and got a 5 star question correct.

My advice here is to reach into the logic of these games. Reach out if you need assistance of any kind, know these rules, know how they interact.

I hope this helps
David