Question

The base and top diameter of a cone is 0.5 m and 0.1 m respectively. The height of the cone is 12 m. What is the volume of frustum of a cone? (Use $\pi$ = 3).

• A. 12.88 m${}^3$
• B. 13.88 m${}^3$
• C. 15.88 m${}^3$
• D. 14.88 m${}^3$

Answer 1

The correct option is D 14.88 m${}^3$

Volume of the frustum cone is $V=\frac{\pi h}{3}(R^2+Rr+r^2)$

D = 0.5 m, d = 0.1 m, h = 4 m

Diameter = radius/2

Radius = 2 $\times$ diameter

Therefore, R = 1 m, r = 0.2 m

$V=(3\times 12)/\left(3\right)[1^2+1\times 0.2+{0.2}^2]$

$=12[1+0.2+0.04]$

$=$ 12[1.24]

$=$ 14.88 m${}^3$