Answer :
Given:
A right rectangular prism is packed with cubes of side length [tex]\dfrac{1}{5}[/tex] inch.
Prism is packed with 15 cubes along the length, 6 cubes along the width, and 5 cubes along the height.
To find:
The volume of the prism
Solution:
Side length of each cube [tex]=\dfrac{1}{5}[/tex] inch.
15 cubes along the length, so length of prism is
[tex]l=15\times \dfrac{1}{5}=3\text{ inches}[/tex]
6 cubes along the width, so width of prism is
[tex]b=6\times \dfrac{1}{5}=\dfrac{6}{5}\text{ inches}[/tex]
5 cubes along the height, so height of prism is
[tex]h=5\times \dfrac{1}{5}=1\text{ inch}[/tex]
Now,
Volume of rectangular prism is
[tex]V=l\times b\times h[/tex]
[tex]V=3\times \dfrac{6}{5}\times 1[/tex]
[tex]V=\dfrac{18}{5}[/tex]
[tex]V=\dfrac{3\times 5+3}{5}[/tex]
[tex]V=3\dfrac{3}{5}\text{ cubic inches}[/tex]
Therefore, the correct option is B.