In the bus station, a bus is dispatched every 3 minutes, and a minibus is dispatched every 7 minutes. If two buses depart at the same time at 6:00, how many times are buses and minibuses dispatched at the same time in 1 hour?
汽车站内每隔3分钟发一辆公交车，7分钟发一辆中巴车，如果6：00两车同时发车，那么在1小时的时间里多少次同时发了公交车和中巴车．
<result>2</result>