A colored ribbon, 40% of the total length is used for the first time, and 14m is used for the second time. At this time, the remaining length of the colored ribbon is just used (1/3). The original length of the colored ribbon is all meters?
一根彩带，第一次用去全长的40%，第二次用去14m，这时剩下的彩带长度正好是用去的(1/3)，这根彩带原来长都是米？
<gadget id="calculator">1 + 3</gadget>
<output>4</output>

<gadget id="calculator">3 / 4</gadget>
<output>3/4 = around 0.75</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">(3/4) - (2/5)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">14 / (7/20)</gadget>
<output>40</output>

<result>40</result>