Solutions
Six persons: F, G, H, I, J and K
1) G got more marks than F and K.
G > F/K
2) K got more marks than J but less marks than H.
H > K > J
3) F got more marks than I but not the highest marks.
F > I
4) G scores more marks than H.
G > H
5) I got third lowest marks.
1 > 2 > 3 > I > 5 > 6
6) From point (1), (2) and (4) it can be concluded that F, K, J and H got less marks than G.
Hence, from point (5) and (6) it can be concluded that G got highest marks.
7) After combining (5) and (6)
G > 2 > 3 > I > 5 > 6
8) F got more marks than K but less than H.
H > F > K
9) After combining (2) and (8)
H > F > K > J

Clearly, possible mark for J according to the given option is 43.