Now there are 60 grams of sugar water with a concentration of 20%, how many grams of sugar need to be added to turn it into sugar water with a concentration of 40%?
现在有浓度为20%的糖水60克，要把它变成浓度为40%的糖水，需要加糖多少克？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">1 - (1/5)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">40 / 100</gadget>
<output>2/5 = around 0.4</output>

<gadget id="calculator">1 - (2/5)</gadget>
<output>3/5 = around 0.6</output>

<gadget id="calculator">(4/5) / (3/5)</gadget>
<output>4/3 = around 1.333333</output>

<gadget id="calculator">60 * (4/3)</gadget>
<output>80</output>

<gadget id="calculator">80 - 60</gadget>
<output>20</output>

<result>20</result>