The distance between the two cities is 900km. Two trains are running towards each other from the two cities at the same time. The express train is 62.5km per hour, which is 1.25 times that of the slow train. How long does it take for the two trains to meet?
两城相距900km，两列火车从两城同时相向而行，快车每小时62.5km，是慢车的1.25倍，两列火车几小时相遇？
<gadget id="calculator">62.5 / 1.25</gadget>
<output>50</output>

<gadget id="calculator">50 + 62.5</gadget>
<output>112.5</output>

<gadget id="calculator">900 / 112.5</gadget>
<output>8</output>

<result>8</result>