There are 150 grams of brine with a concentration of 4% in container A, and several grams of brine with a certain concentration in container B. If 450 grams of brine is taken from B and mixed into A to form a brine with a concentration of 8.2%, find the original What is the concentration of the salt water.
甲容器中有浓度为4%的盐水150克，乙容器中有某种浓度的盐水若干克，如果从乙中取出450克盐水放入甲中混合成浓度为8.2%的盐水，求乙中原来盐水的浓度是多少．
<gadget id="calculator">150 + 450</gadget>
<output>600</output>

<gadget id="calculator">8.2 / 100</gadget>
<output>0.082</output>

<gadget id="calculator">600 * 0.082</gadget>
<output>49.2</output>

<gadget id="calculator">4 / 100</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">150 * (1/25)</gadget>
<output>6</output>

<gadget id="calculator">49.2 - 6</gadget>
<output>43.2</output>

<gadget id="calculator">43.2 / 450</gadget>
<output>0.096</output>

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

<gadget id="calculator">0.096 * 1</gadget>
<output>0.096</output>

<result>0.096</result>