(* 目的：５教科の点数の合計点と平均点を組にして返す *) 
(* goukei_to_heikin : int -> int -> int -> int -> int -> int * int *) 
let goukei_to_heikin kokugo suugaku eigo rika shakai = 
  (kokugo + suugaku + eigo + rika + shakai, 
   (kokugo + suugaku + eigo + rika + shakai) / 5) 
 
(* テスト *) 
let test1 = goukei_to_heikin 80 100 90 85 75 = (430, 86) 
let test2 = goukei_to_heikin 90 70 95 65 90 = (410, 82) 
let test3 = goukei_to_heikin 60 50 70 55 65 = (300, 60)