A jazz group plans to play six pieces - J, K, L, M, N and O - during a set . Each piece will be played exactly thrice. The order in which the pieces are to be played is subject to the following conditions:
N must be played before J and before O.
M must be played later than J.
K must be the third Piece.
If the group plays L first, which piece must be played second ?

Options

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

Answer

D

Explanation

Begin by summarising the information: `Nlt(J+O)`
`JltM`
K = 3
There is one further conclusion that can be drawn. Since N is to be played before J and J before M, N must be played before M.
Enter the additional information in a diagram:
`{:("1 2 3 4 5 6"),("L K"):}`
N must be played before J and O and also M. And this means that N must be played second:
`{:("1 2 3 4 5 6"),("L N K"):}`
Then the order of the other three pieces is not fixed, but these further conclusions are sufficient to answer the question asked.