For a long rope, (2/7) of the total length is cut off for the first time, and 3.6 meters are cut off for the second time, leaving only 1/5 of the total length. How many meters was the rope originally?
一根长绳，第一次截去总长的(2/7)，第二次截去3.6米，还剩下总长的(1/5)，这根绳原来长多少米？
<gadget id="calculator">2 / 7</gadget>
<output>2/7 = around 0.285714</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (2/7) - (1/5)</gadget>
<output>18/35 = around 0.514286</output>

<gadget id="calculator">3.6 / (18/35)</gadget>
<output>7</output>

<result>7</result>