[tex]1\% = \frac{1}{100} = 0,01[/tex]
[tex]1. \ 0,003\% =\frac{0,003}{100} = \frac{0,003\cdot1000}{100\cdot1000} = \frac{3}{100000} = 0,00003\\\\2. \ 0,9\% = \frac{0,9}{100} = \frac{0,9\cdot10}{100\cdot10} = \frac{9}{1000} =0,009\\\\3. \ 0,09\% = \frac{0,09}{100} = \frac{0,09\cdot100}{100\cdot100} = \frac{9}{10000} = 0,0009[/tex]