Build a section of road with a length of x meters. When A completed (1/3), he cooperated with B to build it. It took 12 days to complete the construction.
修筑一段路，长为x米，甲修了(1/3)时，和乙合作修筑，用了12天修完，甲、乙每天共修路多少米．
<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">(2/3) / 12</gadget>
<output>1/18 = around 0.055556</output>

<result>1/18 = around 0.055556</result>