studentencijfers = [ [95, 92, 86],[66, 75, 54],[89, 72, 100],[34, 0, 0] ]

def gemiddelde_per_student(studentencijfers):
    for cijfers in studentencijfers():
        print(cijfers/3)



def gemiddelde_van_alle_studenten(studentencijfers):
   for cijfers in studentencijfers():
       print(cijfers/12)



