Question

A hollow sphere of internal and external diameters 4 cm and 8 cm respectively is melted into a cone of base diameter 8 cm. The height of the cone is

• A. 12
• B. 14
• C. 15
• D. 18

Answer 1

Answer: (B)

14

Answer 2

The correct option is (B):Internal and External radius of sphere are 2 cm and 4 cm
radius of cone = 4 cm.
Let height of cone =$h$ cm
Volume of hollow sphere = Volume of cone
$\frac{4}{3} \pi [( r1)^{3} - (r2)^{3}]=\frac{1}{3} \pi R^{2}h$
$4[(4)^{3} - (2)^{3}]=4^{2}h$
$h = 14cm$