Cars A and B are driving in opposite directions at the same time at the same time. After 3.5 hours, the distance between the two cars is 280 kilometers. Car A travels 42 kilometers per hour. How many kilometers per hour does Car B travel?
甲、乙两车同时从同地反向而行，3.5小时后两车相距280千米，甲车每小时行42千米，乙车每小时行多少千米？
<gadget id="calculator">280 / 3.5</gadget>
<output>80</output>

<gadget id="calculator">80 - 42</gadget>
<output>38</output>

<result>38</result>