We know from rule (4) that L & R cannot both stay open, so if exactly five stations stay open, and only one is closed, it must be L or R. We can thus eliminate answer choices (B), (C), (D).
Now we know that the rest of the stations are open, and rule (2) tells us that if N stays open, L must stay open. Thus, we can eliminate answer choice (A).
R is thus the one that must close (E)
Does this help?
Let me know if you have any further questions.
on November 2, 2019
Hi Irina, if R is out, how come M is still open?
Rule 3: R -> M
(not R -> not M)
Shunheon January 8, 2020
Hi @mamie,
Thanks for the question. Recall that we can't conclude not R -> not M from R - > M. An example might help. If it rains, I will be wet. But that doesn't mean if it doesn't rain, I won't be wet. Maybe I went swimming or something. Hope this helps.
