Mine is for sure PT69.S1.Q14
The test writers really outdid themselves with this one. For some reason this concept is just really interesting to me (the flaw). Perhaps how properties of two things when taken independent of each other can be different when you combine them together.
This relationship is easy to see when you have different color paint etc but in LSAT world I found it super interesting.
Spent 30 minutes trying to understand what was wrong yet still could not understand the flaw until I looked.
Comments
If you google "goblin fern" the second result down is a link to a discussion on the necessary assumption question. The LSAT question on the fern seems to take precedent over discussions of the actual fern. lol!
I think that 69-1-19 is one of the most important questions I have come across in my studies. It has everything: a purported causal relationship, the language of necessity, a subtle hint at an existing contrapositive, an answer choice that reverses the conditional relationship and subtly formulated in a way to get the reader to think the the earthworm is the cause. The LSAT really sets you up on this one. I sometimes think about the kind of person LSAC employs to write questions. Do they have degrees in psychology? Linguistics? How subtly crafted my embedded assumptions were while reading that question is really something to behold and respect. What this question taught me is that sometimes, no matter how fancy and subtly a question is written, at bottom it could be something as simple as a disguised correlation-causation problem. That is a take-away that really reenforces the need to get familiar with the test.