It takes 12 days for A to process a batch of parts alone, 15 days for B to do it alone, and 3 days after A and B work together, there are still 132 parts that have not been processed. If A alone processes this batch of parts, how many more parts should be processed every day?
加工一批零件，甲独干要12天，乙独干要15天，甲乙合干3天后，还剩132个零件没有加工，如果甲单独加工这批零件每天应多加工多少个？
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/12) + (1/15)</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(3/20) * 3</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">1 - (9/20)</gadget>
<output>11/20 = around 0.55</output>

<gadget id="calculator">132 / (11/20) / 12</gadget>
<output>20</output>

<result>20</result>