#[[Flatten@
     Position[LinearProgramming[-#[[;; , 3]], -{#[[;; , 2]]}, -{400},
       {0, 1} & /@ #, Integers], 1], 1]] &@
 {{"map", 9, 150},
  {"compass", 13, 35},
  {"water", 153, 200},
  {"sandwich", 50, 160},
  {"glucose", 15, 60},
  {"tin", 68, 45},
  {"banana", 27, 60},
  {"apple", 39, 40},
  {"cheese", 23, 30},
  {"beer", 52, 10},
  {"suntan cream", 11, 70},
  {"camera", 32, 30},
  {"T-shirt", 24, 15},
  {"trousers", 48, 10},
  {"umbrella", 73, 40},
  {"waterproof trousers", 42, 70},
  {"waterproof overclothes", 43, 75},
  {"note-case", 22, 80},
  {"sunglasses", 7, 20},
  {"towel", 18, 12},
  {"socks", 4, 50},
  {"book", 30, 10}}