Question

The curved surface of a cylindrical pillar is $264m^2$ and its volume is $924m^3$. Find the ratio of its diameter to its height $(Take\pi =\frac{22}{7})$

• A. $7:6$
• B. $6:7$
• C. $3:7$
• D. $7:3$

Answer 1

Answer: (D)

$7:3$

CSA of pillar (cylindrical) $=2\pi rh=264m^2$

Volume of pillar (cylindrical) $=\pi r^{2}h=924m^3$

Now, $\frac{2\pi rh}{\pi r^{2}h}=\frac{264}{924}\Rightarrow r=\frac{2\times 924}{264}=7$

$\therefore$ $2\times \frac{22}{7}\times 7\times h=264\Rightarrow h=\frac{264}{44}=6$

Now $\frac{d}{h}=\frac{2r}{h}=\frac{2\times 7}{6}=\frac{7}{3}or7:3$