Two engineering teams cooperate to complete a project. Team A completes (3/5) of the whole project every day, and team B completes (1/4) of the whole project every day. The two teams worked together for a day, and how much of the project was left unfinished?
两个工程队合作完成一项工程，甲队每天完成全工程的(3/5)，乙队每天完成全工程的(1/4)．两队合作一天，还剩全工程的几分之几没有完成？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">(3/5) + (1/4)</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">(17/20) * 1</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">1 - (17/20)</gadget>
<output>3/20 = around 0.15</output>

<result>3/20 = around 0.15</result>