The master and the apprentice each process a batch of parts. The master completes the task in 2 hours less than the apprentice. If the apprentice makes 180 first, the master starts production. When the master completes the task, the apprentice makes 120 more than the master. It is known that the work efficiency of the apprentice is (3/4) of the master, how many pieces can the master process per hour?
师徒两人各加工一批零件，师傅完成任务要比徒弟完成任务少用2小时，如果徒弟先做180个，师傅才开始生产，当师傅完成任务时，徒弟比师傅多做120个．已知徒弟的工作效率是师傅的(3/4)，师傅每小时加工多少个？
<gadget id="calculator">180 - 120</gadget>
<output>60</output>

<gadget id="calculator">4 / 3</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">(4/3) - 1</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">2 / (1/3)</gadget>
<output>6</output>

<gadget id="calculator">60 / 6</gadget>
<output>10</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">1 - (3/4)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">10 / (1/4)</gadget>
<output>40</output>

<result>40</result>