A candidate for public office plans to visit each of the six cities J, K, L, M, N and O exactly once during her campaign. Her aides are setting up the candidate's schedule according to the following restrictions :
The candidate can visit M only after she has visited both L and N.
The candidate cannot visit N before J.
The second city visited by the candidate must be K.
The candidate could visit any of the following immediately after K , EXCEPT

Options

A. J
B. L
C. M
D. N

Answer

C

Explanation

Begin by summarising the infrormation: `(L+N)ltM`
`JltN`
K=2
Note: Since the candidate cannot visit two simultaneously, the condition " The candidate cannot visit N before J" is equivalent to " She must visit J before N."
As just noted, M cannot be earlier than fifth, so M could not immediately follow K. That the others could follow K, is shown by the following schedules: