Correct Answer - Option 1 : 64
Given:
Diameter of small balls = 21 cm
Diameter of big ball = 84 cm
Formula used:
The volume of a sphere = (4/3)πr3
Calculation:
Diameter of small balls = 21 cm
Radius of small balls = 21/2 cm
Diameter of big ball = 84 cm
Radius of big ball = 42 cm
Let the number of small balls be N
N × (4/3)πr3 = (4/3)πr3
N × (4/3)π × (21/2) × (21/2) × (21/2) = (4/3)π × 42 × 42 × 42
⇒ N = (42 × 42 × 42 × 2 × 2 × 2)/(21 × 21 × 21)
⇒ N = 64
∴ The number of small balls are 64.
