The original plan was to process 25 parts per day on average, and it was completed in 21 days. The actual schedule was 6 days ahead of schedule. How many parts are actually processed per day?
原计划平均每天加工25个零件，21天完成，实际提前了6天，实际每天加工多少个零件．
<gadget id="calculator">21 - 6</gadget>
<output>15</output>

<gadget id="calculator">21 / 15</gadget>
<output>7/5 = around 1.4</output>

<gadget id="calculator">25 * (7/5)</gadget>
<output>35</output>

<result>35</result>