The length of the road from A to B is 392 km. A car travels 168 kilometers in 3 hours. According to this calculation, how many hours will it take to complete the operation? (answer in two ways)
甲地到乙地的公路长392千米．一辆汽车3小时行了168千米．照这样计算，行完全还需要几小时？(用两种方法解答)
<gadget id="calculator">392 - 168</gadget>
<output>224</output>

<gadget id="calculator">168 / 3</gadget>
<output>56</output>

<gadget id="calculator">224 / 56</gadget>
<output>4</output>

<result>4</result>