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.
Which of the following could be the order in which the pieces are played ?

Options

A. K, L, N, O, M, J
B. K, O, N, J, M, L
C. M, J, K, O, L, N
D. N, L, K, J, O, M

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.
Using the first condition that N be played before both J and O. We eliminate (2) and (3). Using the second condition, that J come before M. we eliminate (1). Finally, using the third condition that K be played third. we eliminate (5). So, the one choice that fits all of the conditions is (4).