A certain engineering team completed a project. It was originally planned that 15 workers would complete it in 24 days. In order to meet the construction deadline, it needs to be completed 4 days ahead of schedule. How many workers are actually needed?
某工程队完成一项工程，原计划15个工人24天完成，为了赶工期，需要提前4天完成，这样实际需要安排多少工人？
<gadget id="calculator">24 - 4</gadget>
<output>20</output>

<gadget id="calculator">1 / 15 / 24</gadget>
<output>1/360 = around 0.002778</output>

<gadget id="calculator">20 * (1/360)</gadget>
<output>1/18 = around 0.055556</output>

<gadget id="calculator">1 / (1/18)</gadget>
<output>18</output>

<result>18</result>