The distance between A and B is 7 cm on a 1:3000000 map. Two trains depart from places A and B at the same time and run towards each other. Car A travels 70 kilometers per hour, which is (5/7) the speed of train B. At this speed, how many hours will the two trains meet after leaving?
甲乙两地在1：3000000的地图上相距7厘米．两列火车分别从甲乙两地同时出发相向而行，A车每小时行70千米，是B车速度的(5/7)，照这样的速度，两车开出后几小时相遇？
<gadget id="calculator">1 / 3_000_000</gadget>
<output>1/3_000_000 = around 0</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">70 / (5/7)</gadget>
<output>98</output>

<gadget id="calculator">70 + 98</gadget>
<output>168</output>

<gadget id="calculator">7 / (1/3_000_000) / 100_000 / 168</gadget>
<output>5/4 = around 1.25</output>

<result>5/4 = around 1.25</result>