A liquid medicine, the mass ratio of medicine to water is 5:20, what is the concentration of this liquid medicine?
一种药水，药与水的质量比是5：20，这种药水的浓度是百分之几？
<gadget id="calculator">5 + 20</gadget>
<output>25</output>

<gadget id="calculator">5 / 25</gadget>
<output>1/5 = around 0.2</output>

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

<gadget id="calculator">(1/5) * 1</gadget>
<output>1/5 = around 0.2</output>

<result>1/5 = around 0.2</result>