A, B, and C make a batch of parts together. What A completes is the sum of B and C (1/3), what B completes is the sum of A and C (1/2), and C makes 250 parts. This batch of parts How many are there?
甲、乙、丙三人共做一批零件，甲完成的是乙丙和的(1/3)，乙完成的是甲丙和的(1/2)，丙做了250个，这批零件一共有多少个？
<gadget id="calculator">1 + 3</gadget>
<output>4</output>

<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">(1/4) + (1/3)</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">1 - (7/12)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">250 / (5/12)</gadget>
<output>600</output>

<result>600</result>