In the construction of Olympic venues, a project was originally planned to be completed within the specified date with 52 workers. Later, due to technological innovation, the adoption of new technologies can improve work efficiency by 50%, so it was decided to only arrange 40 workers to work. As a result, the task was completed 6 days ahead of schedule. How long did it take to complete the project?
在奥运会的场馆建设中，一项工程原计划用52个工人在规定的日期内完成，后来因进行技术革新，采用了新技术可以提高工作效率50%，所以决定只安排40个工人去工作，结果还提前6天完成了任务．完成这项工程花了多长时间？
<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 + (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">40 * (3/2)</gadget>
<output>60</output>

<gadget id="calculator">52 / 60</gadget>
<output>13/15 = around 0.866667</output>

<gadget id="calculator">1 - (13/15)</gadget>
<output>2/15 = around 0.133333</output>

<gadget id="calculator">6 / (2/15)</gadget>
<output>45</output>

<gadget id="calculator">45 - 6</gadget>
<output>39</output>

<result>39</result>