December 2017 LSAT Section 4 Question 17

Which one of the following, if substituted for the constraint that if R stays open, then M must also stay open, would...

Elizabeth25 on June 2 at 02:18AM

Slightly confused

so, I read irina description and what I'm taking from this is that I have to get a rule that will be "if r ->m"? I choose (e) because it got me r and m together, but I guess technically in the incorrect reversal but didn't realize it had to be if r ->m, I thought getting them together no matter what was ok. (e) says if m -> not n which would force r (b.c both n and r can't be closed. then the reversal would be if n->then not m not r (since l has to be in b.c of n). it literally gets us R&M together.

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Emil-Kunkin on June 3 at 09:49PM

You're right that the new rule will have the effect that if R then M, without allowing anything that would previously have been banned, or banning anything that would previously have been allowed. E gets us If M then R, which is not the same thing as If R then M. The goal isn't to get them together but to recreate the initial rule. What you're trying to do is to create a new rule that would at times create the same outcome, but would also allow for scenarios where we would have R without M.

Elizabeth25 on June 7 at 02:05AM

ahhh yes i see that. because the r would be the necessary. got it thanks again emil