A solid metallic sphere of diameter 21 cm is melted and recast into a number of smaller cones, each of diameter 3.5 cm and height 3 cm. Find the number of cones so formed.
Given,
Diameter of the sphere = 21 cm
Diameter of the cone = 3.5 cm = 
cm
Height of the cone = 3 cm
So here we have,
Radius of the sphere = 10.5 cm
Radius of the cone = 1.75 cm
Volume of the sphere = 
πr3
= 
Volume of the cone = 
No of cones = 
= 504
So,
504 numbers of cones are formed.
9