The ship goes back and forth between the two piers at the same speed. It travels downstream for 10 hours and goes upstream for 12 hours. If the speed of the water is 4 kilometers per hour, how many kilometers is the distance between the two piers?
轮船以同一速度往返于两码头之间，它顺流而下行了10小时，逆流而上行了12小时，如果水流速度是每小时4千米，则两码头之间的距离是多少千米？
<gadget id="calculator">4 + 4</gadget>
<output>8</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/10) - (1/12)</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">8 / (1/60)</gadget>
<output>480</output>

<result>480</result>