Thanks for the question! We’re being asked here to determine what must be false if N has the same salary as someone else in the firm. Remember that a “Must be False” answer has to be false in all cases; we shouldn’t be able to construct a single possibility that’s true.
So first, let’s take a look at why (D) is right. Let’s say that L is less than H. But we know that H is less than J, who’s less than G, who’s less than M, who’s less than F, who’s less than I, who’s less than K. This chain encompasses everyone except for L and N. Let’s say that L has a salary that is lower than H’s. But we know that N has a salary that’s less than L’s. So the order would have to go
K I F M G J H L N
And so it would be impossible for N to share a salary with anyone else, which violates the original hypothetical, so (D) can’t be true no matter what.
(B), on the other hand, could be true in some cases. Could J’s salary be less than L’s? Sure. Here’s one possible combination:
K L I F M G J H+N
And we can see here that N shares the same salary as H, and that none of the other rules are violated.
Hope this helps! Feel free to ask any other questions that you might have.
Dschramm24May 20, 2020
Just so I make sure i know what I did personally, would the answer be B if the question had said must be true? I think that's where i messed up but wanted to make sure because I too put B
