First think of what 0.2% is as a fraction,
[tex]0.2\%=\frac{0.2}{100}=\frac{2\cdot10^{-1}}{10^2}=\frac{2}{10^3}=\frac{2}{1000}[/tex]
Now multiply the fraction by a fifth,
[tex]\frac{2}{1000}\cdot\frac{1}{5}=\frac{2}{5000}[/tex]
Which then simplifies to,
[tex]\frac{2}{5000}=\boxed{\frac{1}{2500}}[/tex]
Hope this helps :)
