The ratio of parts processed by the master and apprentice is 8:5 per hour. It is known that the apprentice processes 12 fewer parts per hour than the master. How many parts does the apprentice process per hour?
师徒二人每小时加工零件的比是8：5，已知徒弟每小时比师傅少加工12个，徒弟每小时加工零件多少个？
<gadget id="calculator">8 / 5</gadget>
<output>8/5 = around 1.6</output>

<gadget id="calculator">(8/5) - 1</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">12 / (3/5)</gadget>
<output>20</output>

<result>20</result>