If you sell a piece of clothing for 100 yuan, you can earn 25%. If you want to earn 50%, how much do you need to sell it for?
一件衣服若卖100元可赚25%，若要赚50%要卖多少元．
<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">100 / (5/4)</gadget>
<output>80</output>

<gadget id="calculator">50 / 100</gadget>
<output>1/2 = around 0.5</output>

<gadget id="calculator">1 + (1/2)</gadget>
<output>3/2 = around 1.5</output>

<gadget id="calculator">80 * (3/2)</gadget>
<output>120</output>

<result>120</result>