Xiao Ming comes home from school, along a certain bus route, there is a car behind him every 9 minutes along the route, and every 6 minutes he encounters a car head-on, if the bus is at equal intervals If the bus departs and runs non-stop at the same speed, then the bus departs at equal intervals and runs non-stop at the same speed, so what is the time interval for the bus to depart?
小明放学回家，沿着某路公共汽车路线，沿途该路公共汽车每9分钟就有一辆车后面超过他，每6分钟又迎面遇到一辆车，如果这路公共汽车按相等的时间间隔发车，以同样的速度不停地运行，那么公共汽车按相等的时间间隔发车，以同样的速度不停地运行，那么公共汽车的发车时间间隔是多少？
<gadget id="calculator">36 / 5</gadget>
<output>36/5 = around 7.2</output>

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