The radius of the large sphere is double the radius of the small sphere. How many times is the volume of the large sphere than the small sphere? 2 4 6 8

Respuesta :

THe ratio of volumes = ratio of the cubes of the radius so it's

2^3 = 8 (answer)

The volume of a sphere is [tex] \cfrac{4}{3}\ \pi r^3 [/tex]

So, if the small sphere has radius [tex] r [/tex] and the largest sphere has radius [tex] 2r [/tex], their volumes are

[tex] V_1 = \cfrac{4}{3}\ \pi r^3,\quad V_2 = \cfrac{4}{3}\ \pi (2r)^3 = \cfrac{4}{3}\ \pi 8r^3 [/tex]

So, their ratio is

[tex] \cfrac{V_2}{V_1} = \cfrac{\frac{4}{3}\ \pi 8r^3}{\frac{4}{3}\ \pi r^3} = 8 [/tex]