A project needs 12 days to be completed by A alone, and 9 days to be completed by B alone. If A works for 10 days and then leaves, B will continue. How many days will B need to complete?
一项工程，甲单独完成需12天，乙单独完成需9天，如果甲先做10天后有事离开，乙接着做，问乙还需几天完成？
<gadget id="calculator">1 / 12</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(1/12) * 10</gadget>
<output>5/6 = around 0.833333</output>

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

<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/6) / (1/9)</gadget>
<output>3/2 = around 1.5</output>

<result>3/2 = around 1.5</result>