let's firstly convert the mixed fractions to improper fractions and them simply get their product, since the package is just a rectangular prism, its volume will just be width * length * height, and we have all those.
[tex]\stackrel{mixed}{8\frac{3}{4}}\implies \cfrac{8\cdot 4+3}{4}\implies \stackrel{improper}{\cfrac{35}{4}} ~\hfill \stackrel{mixed}{2\frac{6}{7}}\implies \cfrac{2\cdot 7+6}{7}\implies \stackrel{improper}{\cfrac{20}{7}} \\\\[-0.35em] ~\dotfill\\\\ \cfrac{35}{4}\cdot \cfrac{20}{7}\cdot 5\implies \boxed{125}[/tex]
