Explanation:

According to the question,
Let the radius of the smaller ball be = r cm
Now, the radius of the larger ball be = 4r cm
Volume of the smaller sphere = (4/3)∏×r³ …….(i)
Volume of the larger sphere = (4/3)∏×(4r)³ ….(ii)
Now, dividing equation (ii) by (i) .we get,
Number of smaller balls (n)
n =(4/3)∏×(4r)³/(4/3)∏×(r)³ = 64
The volume of the larger sphere is 8 times the volume of the smaller ball.
Curved surface area of the smaller sphere = 4∏×(r) ……..(iii)
Curved surface area of the larger sphere = 4∏×(2r)4r ……..(iv)
Now, dividing equation (iv) by (iii). We get,
Number of smaller spheres (N)
N =     4∏×(2r)² / 4∏×(r)²
= 4
The curved surface area of large ball is four times the curved surface area of the smaller ball