rope is cut off (1/4), and then connected to 42 meters, the result is longer than the original (1/3), how many meters is the original rope?
一条绳子截下(1/4)后，再接上42米，结果比原来长(1/3)，原来的绳子有多少米？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">(1/4) + (1/3)</gadget>
<output>7/12 = around 0.583333</output>

<gadget id="calculator">42 / (7/12)</gadget>
<output>72</output>

<result>72</result>