Add 4 kg of water to 10 kg of salt water with a salt content of 35%, what percentage is the salt content of the salt water?
在含盐率为35%的10千克盐水中加入4千克的水，这时盐水的含盐率是百分之几？
<gadget id="calculator">35 / 100</gadget>
<output>7/20 = around 0.35</output>

<gadget id="calculator">10 + 4</gadget>
<output>14</output>

<gadget id="calculator">(7/20) / 14</gadget>
<output>1/40 = around 0.025</output>

<gadget id="calculator">10 * (1/40)</gadget>
<output>1/4 = around 0.25</output>

<result>1/4 = around 0.25</result>