The total distance is 50 kilometers, the ratio of uphill, flat road and downhill distance is 1:2:3, the time ratio of each section is 4:5:6, and the speed of uphill is 3km/h. time.
总路程是50千米，上坡、平路、下坡的路程比为1：2：3，行各段的时间比4：5：6，上坡速度是3km/h，求行完全程的时间．
<gadget id="calculator">1 + 2 + 3</gadget>
<output>6</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/6) / 3</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">50 * (1/18)</gadget>
<output>25/9 = around 2.777778</output>

<gadget id="calculator">5 / 4</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">50 * (1/18) * (5/4)</gadget>
<output>125/36 = around 3.472222</output>

<gadget id="calculator">6 / 4</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">50 * (1/18) * (3/2)</gadget>
<output>25/6 = around 4.166667</output>

<gadget id="calculator">(25/9) + (125/36) + (25/6)</gadget>
<output>125/12 = around 10.416667</output>

<result>125/12 = around 10.416667</result>