Put 4 grams of salt into 101 grams of water, and then add 20 grams of 5% salt water. What is the concentration of the salt water after stirring well?
在101克水中放进4克盐，然后又加进20克浓度为5%的盐水，搅匀后盐水的浓度为多少．
<gadget id="calculator">4 + 1</gadget>
<output>5</output>

<gadget id="calculator">101 + 4 + 20</gadget>
<output>125</output>

<gadget id="calculator">5 / 125</gadget>
<output>1/25 = around 0.04</output>

<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

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

<gadget id="calculator">(1/25) * 1</gadget>
<output>1/25 = around 0.04</output>

<result>1/25 = around 0.04</result>