There are 600 grams of salt water with a salt content of 10%, how many grams of water can be evaporated to obtain salt water with a salt content of 15%?
有含盐量为10%的盐水600克，蒸发掉多少克水，就可以得到含盐量为15%的盐水？
<gadget id="calculator">10 / 100</gadget>
<output>1/10 = around 0.1</output>

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

<gadget id="calculator">(1/10) / (3/20)</gadget>
<output>2/3 = around 0.666667</output>

<gadget id="calculator">600 * (2/3)</gadget>
<output>400</output>

<gadget id="calculator">600 - 400</gadget>
<output>200</output>

<result>200</result>