Please consider the complete question.
A prism has a length of 9 millimeters, height of 3 and one-half millimeters, and width of 8 and one-half millimeters. What is the volume of the rectangular prism?
We know that volume of rectangular prism is product of its length, width and height.
[tex]V=\text{Length}\times\text{Width}\times \text{Height}[/tex]
[tex]V=9\text{ mm}\times8\frac{1}{2}\text{ mm}\times 3\frac{1}{2}\text{ mm}[/tex]
Let us convert our given mixed fraction into decimal.
[tex]V=9\text{ mm}\times8.5\text{ mm}\times 3.5\text{ mm}[/tex]
[tex]V=267.75\text{ mm}^3[/tex]
Therefore, the volume of the given prism would be [tex]267.75\text{ mm}^3[/tex] and option D is the correct choice.
