E) 5
[tex]5 \frac{6}{10} + \frac{8}{10} = 5 \frac{14}{10} = 6 \frac{4}{10} \\ \\ 4 \frac{2}{5} + 1 \frac{4}{5} = 5 \frac{6}{5} = 6 \frac{1}{6} \\ \\ \\ 3 \frac{3}{4} + 2 \frac{1}{4} = 5 \frac{4}{4} = 6 \\ \\ \\ \\ \\\ \frac{1}{3} + \frac{1}{2} = \frac{2}{6} + \frac{3}{6} = \frac{5}{6} \\ \\ \\ \frac{1}{7} + \frac{2}{3} = \frac{3}{21} + \frac{14}{21} = \frac{17}{21} [/tex]
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