The rope is cut off (1/3), and then connected to 50 meters, the result is 20% longer than the original, how long is the rope?
绳子剪掉(1/3)，再接上50米，结果比原来长20%，绳子长多少米．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

<gadget id="calculator">1 - (1/3)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">(1/5) - (2/3)</gadget>
<output>-7/15 = around -0.466667</output>

<gadget id="calculator">1 + (-7/15)</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">50 / (8/15)</gadget>
<output>375/4 = around 93.75</output>

<result>375/4 = around 93.75</result>