!)

Решение:

Преобразуем смешанные дроби в неправильные:

\( 28\frac{4}{5} = \frac{28 \times 5 + 4}{5} = \frac{140 + 4}{5} = \frac{144}{5} \)

\( 13\frac{5}{7} = \frac{13 \times 7 + 5}{7} = \frac{91 + 5}{7} = \frac{96}{7} \)

\( 6\frac{3}{5} = \frac{6 \times 5 + 3}{5} = \frac{30 + 3}{5} = \frac{33}{5} \)

\( \frac{33}{5} : \frac{2}{3} = \frac{33}{5} \times \frac{3}{2} = \frac{99}{10} \)

\( \frac{144}{5} : \frac{96}{7} = \frac{144}{5} \times \frac{7}{96} = \frac{144 \times 7}{5 \times 96} = \frac{3 \times 48 \times 7}{5 \times 2 \times 48} = \frac{21}{10} \)

\( \frac{21}{10} + \frac{99}{10} = \frac{120}{10} = 12 \)

\( 1\frac{11}{16} = \frac{16 + 11}{16} = \frac{27}{16} \)

\( 2\frac{1}{4} = \frac{2 \times 4 + 1}{4} = \frac{8 + 1}{4} = \frac{9}{4} \)

\( \frac{27}{16} : \frac{9}{4} = \frac{27}{16} \times \frac{4}{9} = \frac{27 \times 4}{16 \times 9} = \frac{3 \times 9 \times 4}{4 \times 4 \times 9} = \frac{3}{4} \)

\( 12 : \frac{3}{4} = 12 \times \frac{4}{3} = \frac{12 \times 4}{3} = 4 \times 4 = 16 \)

Ответ: 16