A plastic rope is cut off by 4 decimeters and then connected to 6 decimeters. At this time, it is longer than the original total length (2/5). What is the original total length of this plastic rope?
一根塑料绳剪去4分米后又接上6分米，这时比原来的全长多了(2/5)，这根塑料绳原来全长多少分米．
<gadget id="calculator">6 - 4</gadget>
<output>2</output>

<gadget id="calculator">2 / 5</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">2 / (2/5)</gadget>
<output>5</output>

<result>5</result>