To build a road, Team A will complete it in 20 days and Team B will complete it in 30 days. Now that the two teams have been working together for 6 days, how much of this road is left unrepaired?
修一条公路，甲队独修20天完成，乙队独修30天完成．现在两队合修6天，还剩下这条公路的几分之几没修？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

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

<gadget id="calculator">(1/20) + (1/30)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/12) * 6</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

<result>1/2 = around 0.5</result>