Two passenger trains, A and B, depart from opposite places at the same time and meet at a distance of 30 kilometers from the midpoint after 6 hours. The slow train travels 60 kilometers per hour, how many kilometers per hour does the express train travel?
甲乙两列客车从两地同时相对出发，6小时后在距中点30千米处相遇，慢车每小时行60千米，快车每小时行多少千米？
<gadget id="calculator">60 * 6</gadget>
<output>360</output>

<gadget id="calculator">30 * 2</gadget>
<output>60</output>

<gadget id="calculator">360 + 60</gadget>
<output>420</output>

<gadget id="calculator">420 / 6</gadget>
<output>70</output>

<result>70</result>