A section of the road is divided into three sections: uphill, flat road and downhill. The distance ratio of each section is 3:4:5. The ratio of the time it takes Chen Hao to complete the three sections by bicycle is 6:5:4. It is known that his uphill speed is 8 kilometers per hour, and the total length of this section is 12 kilometers. How long will it take Chen Hao to complete the journey?
一段路分为上坡、平路和下坡三段，各段路程比依次为3：4：5，陈浩骑自行车行完这三段路所用的时间比为6：5：4．已知他上坡速度是每时8千米，这段路总长12千米，陈浩行完全程需要多长时间？
<gadget id="calculator">3 + 4 + 5</gadget>
<output>12</output>

<gadget id="calculator">3 / 12</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">6 + 5 + 4</gadget>
<output>15</output>

<gadget id="calculator">6 / 15</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(1/4) / 8 / (2/5)</gadget>
<output>5/64 = around 0.078125</output>

<gadget id="calculator">12 * (5/64)</gadget>
<output>15/16 = around 0.9375</output>

<result>15/16 = around 0.9375</result>