canal was dug, the full length (1/4) was dug on the first day, and the full length (2/5) was dug on the second day. A total of 65 meters was dug in two days. How long is this canal in meters?
挖出一条水渠，第一天挖了全长的(1/4)，第二天挖了全长的(2/5)，两天共挖了65米．这条水渠全长多少米？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

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

<gadget id="calculator">(1/4) + (2/5)</gadget>
<output>13/20 = around 0.65</output>

<gadget id="calculator">65 / (13/20)</gadget>
<output>100</output>

<result>100</result>