Three pipes can be used to inject liquid into the container, and the time to fill the container with the first pipe is 10 hours. The time to fill the container with the second and third tubes is 12 hours and 15 hours, respectively. Due to the reduced pressure, the input capacity of each tube is only half of the original. Therefore, it is decided to use three pipes to inject liquid into the container at the same time, and ask how many hours it will take to fill the empty container at this time.
可用三根管向容器中注入液体，采用第一根管注满容器的时间为10小时．采用第二根管和第三根管注满容器的时间分别为12小时和15小时．由于压力降低，每根管的输入能力仅为原来的一半．因此决定用三根管同时向容器中注入液体，问这时注满空容器需要多少小时．
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / 24</gadget>
<output>1/24 = around 0.041667</output>

<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/20) + (1/24) + (1/30)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1 / (1/8)</gadget>
<output>8</output>

<result>8</result>