The distance between A and B is 360 kilometers. It takes a car 5 hours to drive from A to B, and 4 hours to return. What is the average round trip speed of this car in kilometers per hour?
甲乙两地相距360千米，一辆汽车从甲地开往乙地，用了5小时；返回时用了4小时．这辆汽车往返的平均速度是每小时多少千米？
<gadget id="calculator">360 * 2</gadget>
<output>720</output>

<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">720 / 9</gadget>
<output>80</output>

<result>80</result>