Digging a water tank, the full length (1/4) was dug on the first day, the length ratio of the second day to the first day was 5:2, and there was still 1.25 kilometers left to dig. What is the total length of this water tank? km?
挖一条水槽，第一天挖了全长的(1/4)，第二天与第一天挖的长度比是5：2，最后还剩下1.25千米没有挖，这条水槽全长多少千米？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">5 / 2</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">(1/4) * (5/2)</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">1 - (1/4) - (5/8)</gadget>
<output>1/8 = around 0.125</output>

<gadget id="calculator">1.25 / (1/8)</gadget>
<output>10</output>

<result>10</result>