A hollow sphere of internal and external radii 6 cm and 8 cm respectively is melted and recast into small cones of base radius 2 cm and height 8 cm. Find the number of cones.
Volume of metal in hollow sphere = 4/3π(83 – 63)
= 1184/3. Π cm3
Volume of metal in one cone = 1/3πr2h
= 1/3π × 22 × 8
= 32/3π cm3
Number of cones = Volume of metal in sphere/Volume of metal in one cone