Question

The ratio between the curved surface area and the total surface area of a right circular cylinder is $1:2$. Find the volume of the cylinder, if its total surface area is $616c{m}^2$

Answer 1

Curved $S.A=\frac{1}{2}\times 616=308{cm}^2$

Total $SA=616$ ${cm}^2$

Curved area $=2\pi rh=308$

Total area $=2\pi rh+2\pi r^2=616$

${2\pi r}^2=616-308=308$

$r=\sqrt{\frac{308\times 7}{2\times 22}}=7cm$

$2\pi rh=308$

$h=\frac{308\times 7}{2\times 22\times 7}=7cm$