The distance between A and B is 48 kilometers, part of which is uphill and the rest is downhill. A person rides a bicycle from A to B and returns along the same road. It took 4 hours and 12 minutes to go there, and 3 hours and 48 minutes to return. It is known that the uphill speed of the bicycle is 10 kilometers per hour, what is the downhill speed of the bicycle?
甲乙两地相距48千米，其中一部分是上坡路，其余是下坡路．某人骑自行车从甲地到乙地后沿原路返回．去时用了4小时12分，返回时用了3小时48分．已知自行车的上坡速度是每小时10千米，求自行车下坡的速度？
<gadget id="calculator">48 / 10</gadget>
<output>24/5 = around 4.8</output>

<gadget id="calculator">8 - (24/5)</gadget>
<output>16/5 = around 3.2</output>

<gadget id="calculator">48 / (16/5)</gadget>
<output>15</output>

<result>15</result>