A car drives from place A to place B, travels an average of 50 square meters per hour, and arrives in 3 hours. It only took 2.5 hours to return, how many kilometers per hour was the average travel? (Solve with ratio)
一辆汽车从甲地开往乙地，走时平均每小时行50平米，3小时到达．返回时只用了2.5小时，平均每小时行驶多少千米？(用比例解)
<gadget id="calculator">50 * 3</gadget>
<output>150</output>

<gadget id="calculator">150 / 2.5</gadget>
<output>60</output>

<result>60</result>