One job is done by A in 20 days and by B in 30 days. A works for 3 days first, and B works for another 5 days. What percentage of the work is completed?
一件工作，甲独做20天完成，乙独做30天完成．甲先做3天，乙再做5天，共完成这件工作的几分之几？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">(1/20) * 3</gadget>
<output>3/20 = around 0.15</output>

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

<gadget id="calculator">(1/30) * 5</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(3/20) + (1/6)</gadget>
<output>19/60 = around 0.316667</output>

<result>19/60 = around 0.316667</result>