The processing factory needs to process a batch of parts. The master processes 135 parts per hour, and the apprentice processes 20 fewer parts per hour than the master. The master and apprentice cooperate to complete the work in 8 hours. How many parts are there in total?
加工厂要加工一批零件，师傅每小时加工135个，徒弟每小时加工的个数比师傅少20个，师徒合作8小时完成，这批零件一共多少个？
<gadget id="calculator">135 - 20</gadget>
<output>115</output>

<gadget id="calculator">115 + 135</gadget>
<output>250</output>

<gadget id="calculator">250 * 8</gadget>
<output>2_000</output>

<result>2_000</result>