[tex]1 \frac{2}{5} + \frac{1}{3} = \frac{21}{15} + \frac{5}{15} = \frac{26}{15} = \boxed{1 \frac{11}{15}}[/tex]
[tex]2 \frac{3}{8} - \frac{5}{7} = \frac{133}{56} - \frac{40}{56} = \frac{93}{56} = \boxed{1 \frac{37}{56}}[/tex]
[tex]1\frac{3}{5} \cdot \frac{5}{8} = \frac{8}{5} \cdot \frac{5}{8} = \frac{40}{40} = \boxed{1}[/tex]
[tex]2\frac{1}{3} : 1\frac{5}{6} = \frac{7}{3} : \frac{11}{6} = \frac{7}{3} \cdot \frac{6}{11} = \frac{42}{33} = \frac{14}{11} = \boxed{1\frac{3}{11}}[/tex]
