{
  "question_id": 1173,
  "hints": [
    {"hint_level": 1, "hint": "You know how much the tank holds when full (400 L) and how much is in it now (285 L)."},
    {"hint_level": 2, "hint": "To find how much more is needed, subtract the current amount from the full amount."},
    {"hint_level": 3, "hint": "400 - 285 = ?"}
  ]
}