There are 800 grams of liquid medicine with a concentration (that is, the ratio of medicine to liquid medicine) of 5%, and then add 200 grams of water. What is the concentration of the liquid medicine at this time?
有浓度(即药与药水的比)为5%的药水800克，再加入200克水，这时药水浓度为多少．
<gadget id="calculator">5 / 100</gadget>
<output>1/20 = around 0.05</output>

<gadget id="calculator">800 + 200</gadget>
<output>1_000</output>

<gadget id="calculator">(1/20) / 1_000</gadget>
<output>1/20_000 = around 0.00005</output>

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

<gadget id="calculator">800 * (1/20_000) * 1</gadget>
<output>1/25 = around 0.04</output>

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