How much material is wasted when a solid cone of height 24 cm and radius 8 cm is recast into a solid cylinder of radius 6 cm and height 6 cm?

Correct option is C

Given:

Solid cone:
Height = 24 cm
Radius = 8 cm

Solid cylinder:
Height = 6 cm
Radius = 6 cm

Formula Used:

Volume of a cone = $$(1/3) ×π × r^2 × h$$​​
Volume of a cylinder = $$π × r^2 × h$$​​

Solution:

Volume of cone = $$(1/3) × π × 8^2 × 24 = (1/3) × π × 64 × 24 = 512$$​π cubic cm

Volume of cylinder = $$π × 6^2 × 6 = π × 36 ×6 = 216π$$​ cubic cm

Material wasted = Volume of cone - Volume of cylinder
Material wasted = 512π - 216π = 296π cubic cm

Required  percentage   = $$\frac{296}{512}\times100$$

= 57.8%