A project is expected to be completed in 18 days with 15 workers working 4 hours a day. In order to catch up with the construction period, add 3 people and increase the working time by 1 hour per day, so that the project can be completed a few days earlier.
一项工程，预计15个工人每天做4个小时，18天可以完成．为了赶工期，增加3人并且每天工作时间增加1小时，可以提前几天完工．
<gadget id="calculator">15 + 3</gadget>
<output>18</output>

<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">18 / 18 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">15 * 4 * (1/5)</gadget>
<output>12</output>

<gadget id="calculator">18 - 12</gadget>
<output>6</output>

<result>6</result>