Given: Radius of large sphere = 10 cm Number of small spheres = 8 Formula: Volume of sphere = 4/3 × πr3 Volume of large sphere = 4π/3 × 103 Volume of small sphere = 4π/3 × r3 Then, ⇒4π/3×103=8×4π/3×r3 ⇒r3=125 ⇒ r = 5 cm Surface area of small sphere = 4πr2 =4×π×5×5 =100πsq.cm