car travels from A to B at 70 kilometers per hour and arrives in 4 hours. When returning, it is scheduled to return to place A within 3.5 hours. How many kilometers will be traveled per hour? (Solve with ratio)
一辆汽车从甲地到乙地，每小时行了70千米，4小时到达．返来时预定3.5小时回到甲地，每小时要行多少千米？(用比例解)
<gadget id="calculator">70 * 4</gadget>
<output>280</output>

<gadget id="calculator">280 / 3.5</gadget>
<output>80</output>

<result>80</result>