(1/5) of a number is 10 less than its (1/4), what is this number?
一个数的(1/5)比它的(1/4)少10，这个数是多少？
<gadget id="calculator">1 / 4</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">(1/4) - (1/5)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">10 / (1/20)</gadget>
<output>200</output>

<result>200</result>