There are 400 grams of salt water with a concentration of 8%. After boiling, it becomes 10% salt water. How many grams of water has been reduced?
有浓度为8%的盐水400克，经煮沸后，变成10%的盐水．水减少了多少克？
<gadget id="calculator">8 / 100</gadget>
<output>2/25 = around 0.08</output>

<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

<gadget id="calculator">(2/25) / (1/10)</gadget>
<output>4/5 = around 0.8</output>

<gadget id="calculator">400 * (4/5)</gadget>
<output>320</output>

<gadget id="calculator">400 - 320</gadget>
<output>80</output>

<result>80</result>