Two cars depart from places A and B respectively, and meet each other in 3 hours. After the meeting, the car returns on the same road, and the bus continues to move forward. After the car returns to the starting point, it returns again. After 0.5 hours, it meets the bus and asks: How many hours does it take if the bus travels the whole way?
两辆汽车分别从甲、乙两地相对开出，3小时相遇，相遇后，轿车原路返回，公共汽车继续前进，轿车返回到出发地后再次返回经过0.5小时，与公共汽车相遇，问：如果公共汽车行驶全程需要多少小时？
<gadget id="calculator">5 / 36</gadget>
<output>5/36 = around 0.138889</output>

<gadget id="calculator">1 / (5/36)</gadget>
<output>36/5 = around 7.2</output>

<result>36/5 = around 7.2</result>