A lathe worker planned to make 200 parts every day, and completed a batch of tasks in 20 days. He actually made 50 parts more than planned every day. How many days did it take to complete this batch of tasks?
某车工计划每天做200个零件，20天完成一批任务，他实际每天比计划多做50个零件，完成这批任务用了多少天？
<gadget id="calculator">200 + 50</gadget>
<output>250</output>

<gadget id="calculator">20 / 250</gadget>
<output>2/25 = around 0.08</output>

<gadget id="calculator">200 * (2/25)</gadget>
<output>16</output>

<result>16</result>