Answer: Option D
Step-by-step explanation:
You know that the ratio between the radii of the two sphere is 3:5. Knowing this fact, you can calculate the ratio of their volume with this procedure:
[tex]ratio\ volume=\frac{3^3}{5^3}[/tex]
You need to remember that:
[tex]a^3=a*a*a[/tex]
Then, you can rewrite it as:
[tex]ratio\ volume=\frac{3*3*3}{5*5*5}[/tex]
Finally, you get the the ratio of the volumes of the spheres is:
[tex]ratio\ volume=\frac{27}{125}[/tex] or 27:125
This matches with the option D.