Three workers, A, B, and C, work together to complete a batch of parts. The ratio of the number of parts processed by A to the number of parts processed by B is 1:2. C processed (3/5) of this batch of parts, and B processed 120 parts. How many parts are there?
甲乙丙三个工人共同加工完成一批零件，甲加工的个数与乙加工个数的比是1：2，丙加工了这批零件的(3/5)，乙加工了120个，这批零件共多少个？
<gadget id="calculator">3 / 5</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">1 - (3/5)</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 + 2</gadget>
<output>3</output>

<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(2/5) * (2/3)</gadget>
<output>4/15 = around 0.266667</output>

<gadget id="calculator">120 / (4/15)</gadget>
<output>450</output>

<result>450</result>