Four masters A, B, C, and D work together to process a batch of parts. A and B process (1/2) of the total number, and A and C process (1/3) of the total number. Person processed (1/4) of the total amount, how much of the total amount was processed by A.
甲、乙、丙、丁四个师傅共同加工一批零件，甲、乙二人加工了总数的(1/2)，甲、丙二人加工了总数的(1/3)，甲、丁二人加工了总数的(1/4)，甲加工了总数的多少．
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

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

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

<gadget id="calculator">(1/4) - 1</gadget>
<output>-3/4 = around -0.75</output>

<gadget id="calculator">(1/2) + (1/3) + (-3/4)</gadget>
<output>1/12 = around 0.083333</output>

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

<gadget id="calculator">(1/12) / 2</gadget>
<output>1/24 = around 0.041667</output>

<result>1/24 = around 0.041667</result>