Processing a batch of parts, A alone takes 10 hours, and B alone takes 12 hours. Now this batch of parts is evenly distributed to two people to work at the same time. When A completes the task, what fraction of all the parts will B have left?
加工一批零件，甲单独做要10时，乙单独做要12时，现在把这批零件平均分给两人同时做，甲完成任务时，乙还剩全部零件的几分之几？
<gadget id="calculator">1 / 2</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 / 10</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(1/2) / (1/10)</gadget>
<output>5</output>

<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

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

<gadget id="calculator">(1/2) - (5/12)</gadget>
<output>1/12 = around 0.083333</output>

<result>1/12 = around 0.083333</result>