There are 300 grams of brine containing 13% salt in container A, and 700 grams of brine containing 7% salt in container B. Take out the same amount of brine from containers A and B respectively, and pour the one from A into B. The water taken from B is poured into A. Now the concentration of salt water in the two containers of A and B is the same. How many grams of salt water are taken from the two containers respectively?
A容器中有含盐13%的盐水300克，B容器中有含盐7%的盐水700克，分别从A、B容器中取出等量的盐水，把从A中取出的倒入B，把从B中取出的倒入A，现在A、B两容器中盐水浓度相同，问分别从两容器中取出多少克盐水？
<gadget id="calculator">13 / 100</gadget>
<output>13/100 = around 0.13</output>

<gadget id="calculator">300 * (13/100)</gadget>
<output>39</output>

<gadget id="calculator">7 / 100</gadget>
<output>7/100 = around 0.07</output>

<gadget id="calculator">700 * (7/100)</gadget>
<output>49</output>

<gadget id="calculator">39 + 49</gadget>
<output>88</output>

<gadget id="calculator">300 + 700</gadget>
<output>1_000</output>

<gadget id="calculator">88 / 1_000</gadget>
<output>11/125 = around 0.088</output>

<gadget id="calculator">700 * (11/125)</gadget>
<output>308/5 = around 61.6</output>

<gadget id="calculator">(308/5) - 49</gadget>
<output>63/5 = around 12.6</output>

<gadget id="calculator">(13/100) - (7/100)</gadget>
<output>3/50 = around 0.06</output>

<gadget id="calculator">1 * (3/50)</gadget>
<output>3/50 = around 0.06</output>

<gadget id="calculator">(63/5) / (3/50)</gadget>
<output>210</output>

<result>210</result>