To make a batch of parts, the original plan is to make 20 parts per hour, and it will be completed in 30 hours. Actually completed 5 hours ahead of time, how many hours per hour?
做一批零件，原计划每小时做20个，30小时完成．实际提前5小时完成，实际每小时多少个？
<gadget id="calculator">20 * 30</gadget>
<output>600</output>

<gadget id="calculator">30 - 5</gadget>
<output>25</output>

<gadget id="calculator">600 / 25</gadget>
<output>24</output>

<result>24</result>