Two cars, A and B, start from A to B at the same time. Car A travels for 3 hours to reach B, and B travels for 6 hours to reach B. Knowing that B travels 40 kilometers per hour, calculate how much car A travels per hour km?
甲乙两车同时从A地出发开往B地，甲车行驶3小时到达B地，乙车行驶6小时到达B地，已知乙每小时行40千米，算一算甲车每小时行多少千米？
<gadget id="calculator">6 / 3</gadget>
<output>2</output>

<gadget id="calculator">40 * 2</gadget>
<output>80</output>

<result>80</result>