Dilute 360 grams of 95% alcohol solution with water to form a 45% alcohol solution, how many kilograms of water should be added?
把浓度是95%的酒精溶液360克，加水稀释成45%的酒精溶液，需加水多少千克？
<gadget id="calculator">95 / 100</gadget>
<output>19/20 = around 0.95</output>

<gadget id="calculator">45 / 100</gadget>
<output>9/20 = around 0.45</output>

<gadget id="calculator">(19/20) / (9/20)</gadget>
<output>19/9 = around 2.111111</output>

<gadget id="calculator">360 * (19/9)</gadget>
<output>760</output>

<gadget id="calculator">760 - 360</gadget>
<output>400</output>

<result>400</result>