There are 100 grams of salt water with a salt content of 5%. After standing for a period of time, part of the water evaporates. It is measured that the salt content is 8%. How many grams of water evaporated?
有100克含盐5%的盐水，放置一段时间后蒸发了一部分水，测得这时含盐率为8%，蒸发了多少克水．
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">8 / 100</gadget>
<output>2/25 = around 0.08</output>

<gadget id="calculator">(1/20) / (2/25)</gadget>
<output>5/8 = around 0.625</output>

<gadget id="calculator">100 * (5/8)</gadget>
<output>125/2 = around 62.5</output>

<gadget id="calculator">100 - (125/2)</gadget>
<output>75/2 = around 37.5</output>

<result>75/2 = around 37.5</result>