rope is used (1/3) and then connected to 16 meters, which is now longer than the original (1/5). How long is this rope in meters?
一根绳子，用去(1/3)后又接上16米，这时比原来长(1/5)．这根绳子原来是多少米长．
<gadget id="calculator">1 / 3</gadget>
<output>1/3 = around 0.333333</output>

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

<gadget id="calculator">(1/3) + (1/5)</gadget>
<output>8/15 = around 0.533333</output>

<gadget id="calculator">16 / (8/15)</gadget>
<output>30</output>

<result>30</result>