What is the concentration of salt water obtained by mixing 200 g of 20% brine and 300 g of 30% brine?
将200克浓度为20%的盐水和300克浓度为30%的盐水混合在一起，得到的盐水浓度为多少．
<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">200 * (1/5)</gadget>
<output>40</output>

<gadget id="calculator">30 / 100</gadget>
<output>3/10 = around 0.3</output>

<gadget id="calculator">300 * (3/10)</gadget>
<output>90</output>

<gadget id="calculator">40 + 90</gadget>
<output>130</output>

<gadget id="calculator">200 + 300</gadget>
<output>500</output>

<gadget id="calculator">130 / 500</gadget>
<output>13/50 = around 0.26</output>

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

<gadget id="calculator">(13/50) * 1</gadget>
<output>13/50 = around 0.26</output>

<result>13/50 = around 0.26</result>