Add 100 grams of water to 300 grams of salt water with a salt content of 20%, what is the salt content of the new salt water?
在含盐率20%的300克盐水中，加入100克水，新盐水的含盐率是多少？
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">300 * (1/5)</gadget>
<output>60</output>

<gadget id="calculator">300 + 100</gadget>
<output>400</output>

<gadget id="calculator">60 / 400</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">100 / 100</gadget>
<output>1</output>

<gadget id="calculator">(3/20) * 1</gadget>
<output>3/20 = around 0.15</output>

<result>3/20 = around 0.15</result>