A, B, and C work together on a project. A and B have completed (3/4) of the total project, and the amount completed by B and C together accounts for (5/6) of the total project. B has completed What fraction of the total project?
甲、乙、丙三人合做一项工程，甲、乙共完成了总工程的(3/4)，乙和丙完成的量加起来占了总工程的(5/6)，乙完成了总工程的几分之几？
<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">5 / 6</gadget>
<output>5/6 = around 0.833333</output>

<gadget id="calculator">(5/6) - 1</gadget>
<output>-1/6 = around -0.166667</output>

<gadget id="calculator">(3/4) + (-1/6)</gadget>
<output>7/12 = around 0.583333</output>

<result>7/12 = around 0.583333</result>