a) \frac{3\frac{1}{3}+2,25+1}{3}=
\frac{\frac{4}{3}+\frac{9}{4}+1}{3}=
\frac{\frac{16}{12}+\frac{27}{12}+\frac{12}{12}}{3}=
\frac{\frac{55}{12}}{3}=
\frac{55}{12}*\frac{1}{3}=\frac{55}{36}
b) \frac{4,25+0,5+5,44}{3}=\frac{10,19}{3}=\frac{1019}{100}*\frac{1}{3}=\frac{1019}{300}=3\frac{119}{300}