It takes 20 days for team A to repair a section of road alone, and 15 days for team B to repair it alone. After 5 days of joint repair, there is still 1400 meters left. How long is this section of road?
一段工路，甲队单独修要20天，乙队单独修要15天，甲乙合修5天后还剩1400米，这段工路有多长？
<gadget id="calculator">1 / 20</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">1 / 15</gadget>
<output>1/15 = around 0.066667</output>

<gadget id="calculator">(1/20) + (1/15)</gadget>
<output>7/60 = around 0.116667</output>

<gadget id="calculator">(7/60) * 5</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">1 - (7/12)</gadget>
<output>5/12 = around 0.416667</output>

<gadget id="calculator">1_400 / (5/12)</gadget>
<output>3_360</output>

<result>3_360</result>