If the surface area of a sphere is reduced to one-ninth of the area

• Mensuration

If the surface area of a sphere is reduced to one-ninth of the area, its radius reduces to

1. One-fourth
2. One-third
3. One-fifth
4. One-ninth

Answer

Surface Area of Sphere = 4πr²

Since surface are is proportional to r², if the area is reduced by one-ninth, radius must be reduced by one-third.

New radius = √(1/9) = 1/3

The correct option is B.