A batch of parts is jointly produced by A, B, and C. A and B jointly made (2/3) of these parts, and B and C jointly made (3/4). What fraction of this batch of parts did B make?
一批零件由甲、乙、丙三人共同完成，甲乙合做了这些零件的(2/3)，乙丙合做了(3/4)，乙做了这批零件的几分之几？
<gadget id="calculator">2 / 3</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(3/4) - 1</gadget>
<output>-1/4 = around -0.25</output>

<gadget id="calculator">(2/3) + (-1/4)</gadget>
<output>5/12 = around 0.416667</output>

<result>5/12 = around 0.416667</result>