Master Li processes a batch of parts. If he processes 25 parts per hour, it can be completed in 8 hours. If he processes 20 parts per hour, how many hours can he complete it? (Solve with ratio)
李师傅加工一批零件，如果每小时加工25个，8小时可以完成，如果每小时加工20个，多少小时可以完成？(用比例解)
<gadget id="calculator">25 * 8</gadget>
<output>200</output>

<gadget id="calculator">200 / 20</gadget>
<output>10</output>

<result>10</result>