Two trains depart from places A and B which are 2400 kilometers apart at the same time, and meet each other 6 hours later. Car A travels 180 kilometers per hour, how many kilometers per hour does Car B travel?
两列火车分别从相距2400千米的甲乙两地同时相对开出，6小时后相遇．甲车每小时行180千米，乙车每小时行多少千米？
<gadget id="calculator">2_400 / 6</gadget>
<output>400</output>

<gadget id="calculator">400 - 180</gadget>
<output>220</output>

<result>220</result>