Find the volume of a sphere whose surface area is 154 cm².

Surface area of sphere A = 154 cm²
Let, the radius of sphere = r cm
We know that the surface area of sphere = 4πr²
⇒ 154 = 4 × 22/7 × r²
⇒ r² = (154 × 7)/(22×4) = 49/4
⇒ r = √49/4 = 7/2
Volume of sphere = 4/2πr³
= 4/3 × 22/7 × (7/2)³
= 4/3 × 22/7 × 7/2 × 7/2 × 7/2
= 539/3 = 179(2/3) cm³
Hence the volume of sphere is 179(2/3) cm³.