Answer:
4
Explanation:
If the radius of sphere Z is R, and the radius of sphere B is r, then:
Vz = 4/3 π R³
Vb = 4/3 π r³
The volume of sphere Z is 64 times the volume of sphere B, so:
Vz = 64 Vb
4/3 π R³ = 64 (4/3 π r³)
R³ = 64r³
R = 4r
The radius of sphere Z is 4 times the radius of sphere B.