Question

A drinking glass is in the shape of a frustum of a cone of height $12$ cm. The diameters of its two circular ends are $2$ cm and $1$ cm. Find the capacity of the glass.

• A. $4\pi c{m}^3$
• B. $3\pi c{m}^3$
• C. $6\pi c{m}^3$
• D. $7\pi c{m}^3$

Answer 1

The correct option is D $7\pi c{m}^3$

Volume of the frustum cone $=$ $\frac{1}{3}\pi h(R^2+r^2+Rr)$

$=$ $\frac{1}{3}\pi \times 12(1^2+{0.5}^2+0.5)$

$=$ $\frac{1}{3}\pi \times 21$

$=$ $7\pi c{m}^3$