Add 5 kg of water to 20% salt water, the concentration becomes 15%, and after adding how many kilograms of salt, the concentration becomes 32%.
有浓度20%的盐水中加5千克的水，浓度变成15%，再加入多少千克盐后，浓度又变成32%．
<gadget id="calculator">15 + 5</gadget>
<output>20</output>

<gadget id="calculator">15 / 100</gadget>
<output>3/20 = around 0.15</output>

<gadget id="calculator">1 - (3/20)</gadget>
<output>17/20 = around 0.85</output>

<gadget id="calculator">32 / 100</gadget>
<output>8/25 = around 0.32</output>

<gadget id="calculator">1 - (8/25)</gadget>
<output>17/25 = around 0.68</output>

<gadget id="calculator">(17/20) / (17/25)</gadget>
<output>5/4 = around 1.25</output>

<gadget id="calculator">20 * (5/4)</gadget>
<output>25</output>

<gadget id="calculator">25 - 20</gadget>
<output>5</output>

<result>5</result>