fix but

app/helpers/exercises_helper.rb

@@ -56,8 +56,8 @@ module ExercisesHelper
       }
       @ex_sub_array.push(sub_score)
     end
-    @ex_obj_array.sort_by {|k| k[:q_position]}
-    @ex_sub_array.sort_by {|k| k[:q_position]}
+    @ex_obj_array = @ex_obj_array.sort_by {|k| k[:q_position]}
+    @ex_sub_array = @ex_sub_array.sort_by {|k| k[:q_position]}
   end
 
   #试卷的统计结果页面计算各题的