Question

A solid cone of radius 5 cm and height 8 cm is melted and made into small spheres of radius 0.5 cm. The number of spheres formed will be

• A. 800
• B. 600
• C. 400
• D. 200

Answer 1

The correct option is C

400

Number of spheres formed
$=\frac{\text{Volume of the cone}}{\text{Volume of a sphere}}$
$=\frac{\frac{1}{3}\pi \times 5^2\times 8}{\frac{4}{3}\pi \times {\left(\frac{1}{2}\right)}^3}=\frac{25\times 8}{4\times \frac{1}{8}}=400$