How much is the original price, after an increase of 25%, the price is 75 yuan.
原价多少元，增加25%后定价是75元．
<gadget id="calculator">25 / 100</gadget>
<output>1/4 = around 0.25</output>

<gadget id="calculator">1 + (1/4)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">75 / (5/4)</gadget>
<output>60</output>

<result>60</result>