Answer:
[tex]\large\boxed{V=42\dfrac{7}{8}\ ft^3}[/tex]
Step-by-step explanation:
The formula of a volume of a cube:
[tex]V=a^3[/tex]
a - edge
We have
[tex]a=3\dfrac{1}{2}\ ft[/tex]
Convert to the improper fraction:
[tex]a=\dfrac{3\cdot2+1}{2}=\dfrac{7}{2}\ ft[/tex]
Substitute to the formula of a volume:
[tex]V=\left(\dfrac{7}{2}\right)^3=\dfrac{7^3}{2^3}=\dfrac{343}{8}=42\dfrac{7}{8}\ ft^3[/tex]
