The convoy transported a batch of relief supplies to the disaster area. It traveled 60 kilometers per hour, arrived in the disaster area in 6.5 hours, and returned at 78 kilometers per hour. How long will it take for the convoy to return to the starting point? (use ratio to solve)
车队向灾区运送一批救灾物资，运去时每小时60千米，6.5小时到达灾区，回来时每小时78千米，车队要多长时间能够返回出发地点？(用比例来解)
<gadget id="calculator">60 * 6.5</gadget>
<output>390</output>

<gadget id="calculator">390 / 78</gadget>
<output>5</output>

<result>5</result>