A, B, and C work together to process a batch of parts, and A processes 20 more parts than B, and the parts processed by C belong to B (4/5), and the parts processed by A are (5) /6), how many parts does B process.
甲，乙，丙三人共同加工一批零件，甲比乙多加工零件20个，丙加工的零件是乙的(4/5)，甲加工零件是乙、丙两人加工零件总数的(5/6)，则乙加工零件多少个．
<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">4 + 5</gadget>
<output>9</output>

<gadget id="calculator">5 / 9</gadget>
<output>5/9 = around 0.555556</output>

<gadget id="calculator">(5/6) - (5/9)</gadget>
<output>5/18 = around 0.277778</output>

<gadget id="calculator">20 / (5/18)</gadget>
<output>72</output>

<gadget id="calculator">72 * (5/9)</gadget>
<output>40</output>

<result>40</result>