(1/5) of a number is 50 more than its 15%, what is this number?
一个数的(1/5)比它的15%多50，这个数是多少？
<gadget id="calculator">1 / 5</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">(1/5) - (3/20)</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">50 / (1/20)</gadget>
<output>1_000</output>

<result>1_000</result>