The engineering team repairs a canal, working 6 hours a day, and can complete the task in 12 days. If the work efficiency remains the same and you work 8 hours a day, how many days can you complete the task in advance?
工程队修一条水渠，每天工作6小时，12天可以完成任务．如果工作效率不变，每天工作8小时，则可以提前多少天完成任务．
<gadget id="calculator">6 * 12</gadget>
<output>72</output>

<gadget id="calculator">1 / 72</gadget>
<output>1/72 = around 0.013889</output>

<gadget id="calculator">(1/72) * 8</gadget>
<output>1/9 = around 0.111111</output>

<gadget id="calculator">1 / (1/9)</gadget>
<output>9</output>

<gadget id="calculator">12 - 9</gadget>
<output>3</output>

<result>3</result>