A certain engineering team repairs a road. It repairs the full length (3/20) on the first day, and the full length (1/5) on the second day. What fraction of the length has not been repaired?
某工程队修一条公路，第一天修了全长的(3/20)，第二天修了全长的(1/5)，第三天修的等于前两天修的总和，还剩下全长的几分之几没修？
<gadget id="calculator">3 / 20</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/5) + (3/20)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">(3/20) + (1/5) + (7/20)</gadget>
<output>7/10 = around 0.7</output>

<gadget id="calculator">1 - (7/10)</gadget>
<output>3/10 = around 0.3</output>

<result>3/10 = around 0.3</result>