There are several liters of salt water with a concentration of 3%, and the concentration becomes 2% after adding a glass of water. How many cups of water must be added to obtain 1% brine.
有浓度为3%的盐水若干升，加入一杯水后浓度变为2%．要得到浓度为1%的盐水，还要加多少杯水．
<gadget id="calculator">3 / 100</gadget>
<output>3/100 = around 0.03</output>

<gadget id="calculator">0.03 - 0.02</gadget>
<output>0.01</output>

<gadget id="calculator">1 / 100</gadget>
<output>1/100 = around 0.01</output>

<gadget id="calculator">0.02 / 0.01 / (1/100)</gadget>
<output>200</output>

<gadget id="calculator">(3/100) * 200</gadget>
<output>6</output>

<gadget id="calculator">0.02 / 0.01</gadget>
<output>2</output>

<gadget id="calculator">2 + 1</gadget>
<output>3</output>

<gadget id="calculator">6 - 3</gadget>
<output>3</output>

<result>3</result>