Mix 60 grams of 5% brine and 40 grams of 20% brine. Pour out 10 grams and add 10 grams of water. What is the concentration of the brine now?
5%的盐水60克，20%的盐水40克，混合在一起．倒掉10克，再加入10克水，现在的盐水浓度是多少？
<gadget id="calculator">40 - 10</gadget>
<output>30</output>

<gadget id="calculator">60 + 30</gadget>
<output>90</output>

<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">60 * (1/20)</gadget>
<output>3</output>

<gadget id="calculator">20 / 100</gadget>
<output>1/5 = around 0.2</output>

<gadget id="calculator">40 * (1/5)</gadget>
<output>8</output>

<gadget id="calculator">3 + 8</gadget>
<output>11</output>

<gadget id="calculator">60 + 40</gadget>
<output>100</output>

<gadget id="calculator">11 / 100</gadget>
<output>11/100 = around 0.11</output>

<gadget id="calculator">(11/100) / 100</gadget>
<output>11/10_000 = around 0.0011</output>

<gadget id="calculator">90 * (11/10_000)</gadget>
<output>99/1_000 = around 0.099</output>

<result>99/1_000 = around 0.099</result>