Question

If a right circular cone of height 24 cm has a volume of 1232 $c{m}^3$, then the area of its curved surface is:

• A. 154
• B. 550
• C. 1254
• D. 1357

Answer 1

The correct option is B

550

$Volume=\frac{1}{3}\times \frac{22}{7}\times r^2\times 24=1232r^2=\left(\frac{1232\times 7\times 3}{22\times 24}\right)=49r=7.$

Now, r = 7 cm, h = 24 cm.

So, $l=\sqrt{{\left(7\right)}^2+{\left(24\right)}^2}=25cm$

$\therefore$ Curved surface area = $\pi rl=\left(\frac{22}{7}\times 7\times 25\right)c{m}^2=550c{m}^2$