$a)$  

$1,2=1\frac{2}{10}=1\frac{1}{5}$  

$4,75=4\frac{75}{100}=4\frac{3}{4}$  

$0,4=\frac{4}{10}=\frac{2}{5}$  

 

$b)$  

$0,2=\frac{2}{10}=\frac{1}{5}$  

$1,25=1\frac{25}{100}=1\frac{1}{4}$  

$3,5=3\frac{5}{10}=3\frac{1}{2}$  

 

$c)$  

$0,08=\frac{8}{100}=\frac{2}{25}$  

$2,875=2\frac{875}{1000}=2\frac{35}{40}=2\frac{7}{8}$

$0,125=\frac{125}{1000}=\frac{5}{40}=\frac{1}{8}$