Two engineering teams, A and B, repair a canal. If it is done alone, A needs 20 days, and B needs 30 days; now the two teams are working together, when completing (3/4) of the task, team A has repaired 72 meters more than team B. How many meters is this canal?
甲乙两个工程队修一条水渠．如果单独完成，甲需20天，乙需30天；现在两队合修，当完成任务的(3/4)时，甲队比乙队多修了72米．这条水渠长多少米？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / 30</gadget>
<output>1/30 = around 0.033333</output>

<gadget id="calculator">(1/20) - (1/30)</gadget>
<output>1/60 = around 0.016667</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">(1/20) + (1/30)</gadget>
<output>1/12 = around 0.083333</output>

<gadget id="calculator">(3/4) / (1/12)</gadget>
<output>9</output>

<gadget id="calculator">(1/60) * 9</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">72 / (3/20)</gadget>
<output>480</output>

<result>480</result>