Mix 100 grams of 5% salt water with 300 grams of 7% salt water to get 400 grams of salt water.
100克含盐5%的食盐水与300克含盐7%的食盐水混合，得到400克含盐多少的食盐水．
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">100 * (1/20)</gadget>
<output>5</output>

<gadget id="calculator">7 / 100</gadget>
<output>7/100 = around 0.07</output>

<gadget id="calculator">300 * (7/100)</gadget>
<output>21</output>

<gadget id="calculator">5 + 21</gadget>
<output>26</output>

<gadget id="calculator">26 / 400</gadget>
<output>13/200 = around 0.065</output>

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

<gadget id="calculator">(13/200) * 1</gadget>
<output>13/200 = around 0.065</output>

<result>13/200 = around 0.065</result>