There are 60 tons of goods on the station, which can be transported by car A in 10 hours and by car B in 15 hours. If two cars are transported at the same time, how many hours can they be transported.
车站上有60吨货物，用甲车10小时可以运完，用乙车15小时可以运完．如果两车同时运多少小时可以运完．
<gadget id="calculator">60 / 10</gadget>
<output>6</output>

<gadget id="calculator">60 / 15</gadget>
<output>4</output>

<gadget id="calculator">6 + 4</gadget>
<output>10</output>

<result>6</result>