Two engineering teams, A and B, dig a canal. It takes 8 days for team A to complete the digging alone, and 12 days for team B to complete the digging alone. How many days did Team B dig?
甲、乙两个工程队挖一条水渠，甲队单独挖要8天完成，乙队单独挖要12天完成，现在两队同时挖了几天后，乙队调走，余下的甲队在4天内挖完，乙队挖了多少天？
<gadget id="calculator">1 / 8</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">(1/8) * 4</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 - (1/2)</gadget>
<output>1/2 = around 0.5</output>

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

<gadget id="calculator">(1/8) + (1/12)</gadget>
<output>5/24 = around 0.208333</output>

<gadget id="calculator">(1/2) / (5/24)</gadget>
<output>12/5 = around 2.4</output>

<result>12/5 = around 2.4</result>