A bundle of rope, after using up 7 meters of the full length (2/5), there are still 20 meters left, how long is the bundle of rope?
一捆绳子，用去全长的(2/5)还多7米后，还剩20米，这捆绳多少长？
<gadget id="calculator">7 + 20</gadget>
<output>27</output>

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

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">27 / (3/5)</gadget>
<output>45</output>

<result>45</result>