Xiao Liang and Xiao Qiang climb the mountain to look far away, travel 12 kilometers per hour up the mountain, and arrive in (5/6) hours. It only took (2/5) hours to go back along the original road when going down the mountain. How many kilometers per hour is the average return trip?
小亮和小强登山望远，上山每小时行12千米，(5/6)小时到达．下山时沿原路返回只用了(2/5)小时，返回平均每小时行多少千米？
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(5/6) / (2/5)</gadget>
<output>25/12 = around 2.083333</output>

<gadget id="calculator">12 * (25/12)</gadget>
<output>25</output>

<result>25</result>