A factory processes a batch of parts. The ratio of the number of processed parts to the number of unprocessed parts is 5:7, and the number of processed parts is 120 less than the number of unprocessed parts. How many parts are there in this batch?
某厂加工一批零件，加工的零件个数与未加工的零件个数比是5：7，加工的零件比未加工的少120个，这批零件共有多少个？
<gadget id="calculator">7 - 5</gadget>
<output>2</output>

<gadget id="calculator">120 / 2</gadget>
<output>60</output>

<gadget id="calculator">5 + 7</gadget>
<output>12</output>

<gadget id="calculator">60 * 12</gadget>
<output>720</output>

<result>720</result>