How many grams of water can be added to 80 grams of sugar water with a concentration of 20% to obtain sugar water with a concentration of 8%.
浓度为20%的80克糖水中，加多少克水就得到浓度为8%的糖水．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">80 * (1/5)</gadget>
<output>16</output>

<gadget id="calculator">8 / 100</gadget>
<output>2/25 = around 0.08</output>

<gadget id="calculator">16 / (2/25)</gadget>
<output>200</output>

<gadget id="calculator">200 - 80</gadget>
<output>120</output>

<result>120</result>