A sphere is placed in an inverted hollow conical vessel of base radius 7 cm and vertical height 24 cm. If the highest point of the sphere is at the level of the base of the cone, then what is the ratio of the volume of the sphere to that of the conical vessel?
1
63 ∶ 256
2
21 ∶ 64
3
63 ∶ 128
4
More than one of the above
5
None of the above