The master and the apprentice processed a batch of parts at the same time. When the task was completed, the master processed 30 more parts than the apprentice. It is known that it takes 6 hours for the master and 10 hours for the apprentice to process these parts alone. How many parts are there in total?
师徒二人同时加工一批零件，完成任务时，师傅比徒弟多加工了30个．已知单独加工完这批零件，师傅要6小时，徒弟要10小时．这批零件一共有多少个？
<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/6) + (1/10)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">1 / (4/15)</gadget>
<output>15/4 = around 3.75</output>

<gadget id="calculator">(15/4) * (1/6)</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">(15/4) * (1/10)</gadget>
<output>3/8 = around 0.375</output>

<gadget id="calculator">(5/8) - (3/8)</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">30 / (1/4)</gadget>
<output>120</output>

<result>120</result>