DRDO Multi tasking staff Model paper 8

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