A road with a total length of 60 kilometers is divided into three sections: uphill, flat, and downhill. The ratio of the length of each section is 1:2:3, and the ratio of the time it takes for Uncle Zhang to ride through each section is 3:4. : 5. It is known that he is cycling at a speed of 25 kilometers per hour on a flat road. How long did it take him to complete the trip?
一条公路全长60千米，分成上坡、平路、下坡三段，各段路程的长度之比是1：2：3，张叔叔骑车经过各段路所用时间之比是3：4：5．已知他在平路上骑车速度是每小时25千米．他行完全程用了多长时间？
<gadget id="calculator">1 + 2 + 3</gadget>
<output>6</output>

<gadget id="calculator">2 / 6</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">3 + 4 + 5</gadget>
<output>12</output>

<gadget id="calculator">4 / 12</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/3) / 25 / (1/3)</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">60 * (1/25)</gadget>
<output>12/5 = around 2.4</output>

<result>12/5 = around 2.4</result>