The length of the railway between A and B is 693 km. A passenger train and a freight train depart from two places at 9:00 a.m. at the same time and run opposite each other. The passenger car travels 70 kilometers per hour and the truck travels 56 kilometers per hour. After how many hours did the two cars meet?
甲、乙两地间铁路长693千米．一列客车和一列货车分别从两地同时在上午9时开出，相对而行．客车每小时行70千米，货车每小时行56千米．经过几小时两车相遇？
<gadget id="calculator">70 + 56</gadget>
<output>126</output>

<gadget id="calculator">693 / 126</gadget>
<output>11/2 = around 5.5</output>

<result>11/2 = around 5.5</result>