When to implement Sufficient/Necessary conditions into logic game rules.

HailMaryLSAT

Hello everyone,

I've been tackling LG for some time now, and it seems that practice is paying off. However, in/out LG games still seem to tank my score when I am doing PTs. Therefore, I've been trying to target in/out games specifically, showing me what I may not be fundamentally understanding.

My main problem with in/out is S/N rules, mainly, when do conditional relationships trigger. I will attach two links to help explain my issue.

https://7sage.com/lsat_explanations/lsat-93-section-4-game-3/ (PT 93 S4 G3)

https://7sage.com/lsat_explanations/lsat-61-section-3-game-1/ (PT61 S3 G1)

For example, in PT 93, JY explains that the first rule of the game is based on a conditional relationship. Though the presence of H or G (or both) being in means F is also in, it is suggested that F can be in by itself, meaning one (or both) of H and G can be out. Okay, that makes sense. That is the contrapositive of the rule. From now on, when faced with an in/out game, I will look at the relationship with even more skepticism.

However, this same skepticism created even more doubt when I would drill with other in/out games. In PT 61, I tried applying the same rules of conditional relationship to Q1. Normally, this question would have been easy, but since I was trying to gauge the relationship between rule #3, it came down to choosing either A or C. I picked C, despite knowing A would have been my usual answer. Of course, that was the only question I got wrong, because I didn't know how to apply the conditional relationship.

So far my intuition is telling me that such a conditional relationship similar to PT 93 is only when there is an "if"->"then" clause. I hope someone could let me know if that is the appropriate method of thinking when approaching conditional relationship, and if there are other methods to better clarify?

AlexLSAT.

I think you are focusing too much on the conditional relationships and not enough on the inferences that come with in/out games. A common inference with in/out games is that when one side is filled, the rest of the pieces have to flow into the other side (because they have no where else to go.) Question 3 is a clear cut example of this.

We know we have 2 driver spots total, and we have two passengers that need a certain driver in their group. L takes one of the two driver spots from us. This means that F HAS to be the driver for the other group because we have two passengers that still need their driver and only one more driver spot, and F is the only possible shared driver between the two of them. The last piece not accounted for is K (which could go in either spot) and that is why A is the correct answer for 3.

In addition, the wrong answer you chose could have been avoided by realizing that since L is the driver, that means G is a passenger and can't drive. If we do not have F or G able to drive H, it doesn't obey rule 1.