If the volume of a right circular cone of height 9 cm

Home » Aptitude » Volume and Surface Area of Solid Figures » Question

If the volume of a right circular cone of height 9 cm is 48π cm³, then find the diameter of its base. ?

1. 8 cm
2. 4 cm
3. 7 cm
4. 11 cm

Correct Option: A

volume = 48 π cm³ and h = 9 cm
∴ (1/3)πr²h = 48π
⇒ (1/3) x π x r² x 9 = 48π
∴ r² = (48π x 3) / (π x 9) = 16
∴ r = √16 = 4 cm
∴ Diameter = 2r = 2 x 4 = 8 cm