It takes 9 days for Team A to transport a batch of goods alone, and it takes 12 days for Team B to complete the transport alone. Now Team A will transport it for 6 days first, and Team B will finish transporting the rest. How many days will it take to complete?
运送一批货物甲队独运需要9天完成，乙队独运需要12天完成．现在由甲队先运6天，剩下的由乙队运完，还要几天完成？
<gadget id="calculator">1 / 9</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">(1/9) * 6</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">1 - (2/3)</gadget>
<output>1/3 = around 0.333333</output>

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

<gadget id="calculator">(1/3) / (1/12)</gadget>
<output>4</output>

<result>4</result>