The distance between A and B is 315 kilometers, and a car travels 135 kilometers in 3 hours. According to this calculation, how many hours will it take to complete the journey? (Solve with ratio)
甲乙两地的距离是315千米，一辆汽车3小时行了135千米，照这样计算，行驶完全程需要几小时？(用比例解)
<gadget id="calculator">135 / 3</gadget>
<output>45</output>

<gadget id="calculator">315 / 45</gadget>
<output>7</output>

<result>7</result>