\[7\frac{3^{\backslash 6}}{8} + 9\frac{7^{\backslash 3}}{16} + 11\frac{7^{\backslash 4}}{12} =\]
\[= 7\frac{18}{48} + 9\frac{21}{48} + 11\frac{28}{48} = 27\frac{67}{48} =\]
\[= 28\frac{19}{48}\]