There are 40 grams of brine with 20% salt content, how many grams of water need to be added to make brine with 8% salt content?
有含盐20%的盐水40克，要配制成含盐8%的盐水，需加水多少克？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">(1/5) / (2/25)</gadget>
<output>5/2 = around 2.5</output>

<gadget id="calculator">40 * (5/2)</gadget>
<output>100</output>

<gadget id="calculator">100 - 40</gadget>
<output>60</output>

<result>60</result>