Question

If a cone of radius 15 cm and height 60 cm is melted and recast to form a sphere, then radius of sphere = .

• A. 10 cm
• B. 15 cm
• C. 12 cm
• D. 16 cm

Answer 1

The correct option is B 15 cm

Given: Radius of the cone, $r=15cm$
Height of the cone $=60cm$

Let the radius of sphere be $R$.
Since the cone is melted and moulded to form a sphere, the volume of sphere will be equal to volume of cone.

$\therefore \frac{4}{3}\pi R^3=\frac{1}{3}\pi r^{2}h4R^3=15\times 15\times 60R^3={15}^{3}R=15cm$
$\therefore$ Radius of the sphere is $15cm$.