A road with a total length of 90 kilometers is divided into three sections: uphill, flat road and downhill. The ratio of the length of each section of the journey is 1:2:3, and the ratio of the time it takes Wang Ming to cycle through each section of the road is 3:4:5. It is known that he is cycling at a speed of 25 kilometers per hour on a flat slope. How long did it take him to complete the trip?
一条公路全长90千米，分成上坡、平路、下坡三段．各段路程的长度之比为1：2：3，王明骑车经过各段路所用的时间比是3：4：5．已知他在平坡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">90 * (1/3)</gadget>
<output>30</output>

<gadget id="calculator">30 / 25</gadget>
<output>6/5 = around 1.2</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">(6/5) / (1/3)</gadget>
<output>18/5 = around 3.6</output>

<result>18/5 = around 3.6</result>