Question

The volume of a cylinder of height 4 cm and total surface area 484 $c{m}^2$ is

• A. 612 $c{m}^3$
• B. 610 $c{m}^3$
• C. 616 $c{m}^3$
• D. 620 $c{m}^3$

Answer 1

The correct option is C 616 $c{m}^3$

$2\pi r(h+r)=484$
$\Rightarrow 2\times \frac{22}{7}r(4+r)=484$
$r(4+r)=\frac{484\times 7}{2\times 22}=77$
$r^2+4r-77=0$
$(r-7)(r+11)=0\Rightarrow r=7cm$
Volume of cylinder $=\pi r^{2}h$
$=\frac{22}{7}\times {\left(7\right)}^2\times 4$
$=22\times 28=616c{m}^3$