A workshop needs to produce 900 parts, and it is planned to finish in 20 days. Due to technological improvement, 5 parts are actually produced every day more than planned. How many days did it actually take to complete the task?
某车间要生产900个零件，计划用20天完成，由于技术改进，实际每天比计划多生产了5个零件．完成这项任务实际用了多少天？
<gadget id="calculator">900 / 20</gadget>
<output>45</output>

<gadget id="calculator">45 + 5</gadget>
<output>50</output>

<gadget id="calculator">900 / 50</gadget>
<output>18</output>

<result>18</result>