The master and the apprentice process a batch of parts at the same time. The master processes 12 pieces per hour, and the apprentice processes 8 pieces per hour. When the task is completed, the master processes 6 more parts than the apprentice. How many hours did they spend processing this part?
师徒两人同时加工一批零件，师傅每小时加工12个，徒弟每小时加工8个，完成任务时师傅比徒弟多加工6个，他们加工这个零件共用了几小时？
<gadget id="calculator">12 - 8</gadget>
<output>4</output>

<gadget id="calculator">6 / 4</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>