To build a diversion canal, team A will repair it in 3 days (1/20), team B will repair it in 5 days (1/10), and the two teams will repair it in 6 days.
修一条引水渠，甲队3天修(1/20)，乙队5天修(1/10)，两队合修6天，剩几分之几没有修？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/20) / 3</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/10) / 5</gadget>
<output>1/50 = around 0.02</output>

<gadget id="calculator">(1/60) + (1/50)</gadget>
<output>11/300 = around 0.036667</output>

<gadget id="calculator">6 * (11/300)</gadget>
<output>11/50 = around 0.22</output>

<gadget id="calculator">1 - (11/50)</gadget>
<output>39/50 = around 0.78</output>

<result>39/50 = around 0.78</result>