A rope of 500 meters, the first use of the full length (1/4), is equivalent to the second (5/7). How much rice did you use the second time?
一根绳子500米，第一次用去全长的(1/4)，相当于第二次的(5/7)．第二次用去多少米？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">5 / 7</gadget>
<output>5/7 = around 0.714286</output>

<gadget id="calculator">(1/4) / (5/7)</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">500 * (7/20)</gadget>
<output>175</output>

<result>175</result>