The distance between A and B is 480km. Two cars A and B drive from A and B at the same time. After 3 hours, the distance is still 30km. Car A travels 80km per hour. How many kilometers per hour does B travel?
A、B两地相距480km，甲、乙两辆汽车同时从A、B两地相对开出，3小时后还相距30km，甲车每小时行80km，乙车每小时行多少千米？
<gadget id="calculator">480 - 30</gadget>
<output>450</output>

<gadget id="calculator">450 / 3</gadget>
<output>150</output>

<gadget id="calculator">150 - 80</gadget>
<output>70</output>

<result>70</result>