Master Liu needs to process a batch of parts, 40 parts per hour, which can be completed in 3 hours. If the task is to be completed half an hour earlier, how many parts per hour will be processed? (Solved using ratio method)
刘师傅要加工一批零件，每小时加工40个，3小时可以完成，如果要提前半小时完成任务，每小时加工多少个零件？(用比例的方法解)
<gadget id="calculator">40 * 3</gadget>
<output>120</output>

<gadget id="calculator">3 - 0.5</gadget>
<output>2.5</output>

<gadget id="calculator">120 / 2.5</gadget>
<output>48</output>

<result>48</result>