A, B, C, and D work together to make a batch of parts, A gets 20 more parts from this batch (1/6), B gets 30 less from the remaining (1/2), and C gets the rest (5/9) had 10 more, and the rest was given to Ding. As a result, the four got the same amount. How many parts are there in this batch? ．
甲、乙、丙、丁合做一批零件，甲分得这批零件的(1/6)多20个，乙分得剩下的(1/2)少30个，丙又分得剩下的(5/9)多10个，最后剩下的给了丁，结果四人分得同样多．这批零件有多少个？．
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 6</gadget>
<output>1/6 = around 0.166667</output>

<gadget id="calculator">(1/4) - (1/6)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">20 / (1/12)</gadget>
<output>240</output>

<result>240</result>