$a)\frac{3}{4}+\frac{3}{4}=\frac{6}{4}=1\frac{1}{2}$

$b)\frac{4}{9}+\frac{7}{9}=\frac{11}{9}=1\frac{2}{9}$

$c)\frac{8}{10}+\frac{7}{10}=\frac{15}{10}=1\frac{5}{10}$

$d)\frac{12}{17}+\frac{7}{17}=\frac{19}{17}=1\frac{2}{17}$

$e)\frac{27}{40}+\frac{23}{40}=\frac{50}{40}=1\frac{10}{40}$

$f)\frac{28}{50}+\frac{33}{50}=\frac{61}{50}=1\frac{11}{50}$