Add 3 grams of salt and 9 grams of water to 20% salt water, what is the percentage of salt in the salt water?
在含盐20%的盐水中，加入3克盐和9克水，这时盐水含盐百分比是大于多少
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>