$a)\frac{1}{4}+0,7=0,25+0,7=0,95$  

$b)\frac{1}{2}-0,4=0,5-0,4=0,1$  

$c)\frac{3}{8}-0,15=0,375-0,15=0,225$  

$d)\frac{1}{8}+2,5=\frac{1}{8}+2\frac{4}{8}=2\frac{5}{8}$  

$e)1\frac{1}{4}\cdot 0,3=\frac{5}{4}\cdot 0,3=\frac{{\sout{5}}^1}{4}\cdot \frac{3}{{\sout{10}}^2}=\frac{3}{8}$  

$f)\frac{2}{5}:0,08=\frac{2}{5}:\frac{8}{100}=\frac{{\sout{2}}^1}{{\sout{5}}^1}\cdot \frac{{\sout{100}}^{20}}{{\sout{8}}^4}=\frac{20}{4}=5$  

$g)\frac{1}{5}\cdot 0,6=0,2\cdot 0,6=0,12$  

$h)1\frac{3}{4}:0,4=\frac{7}{4}:\frac{4}{10}=\frac{7}{{\sout{4}}^2}\cdot \frac{{\sout{10}}^5}{4}=\frac{35}{8}=4\frac{3}{8}$