The total surface area of a cylinder is 462 cm2. Its curved surface area is one-third of its total surface area. Find the volume of the cylinder.
Total surface area = 462 cm2
Given: Curved surface area $=\frac{1}{3} \times$ total surface area $=\frac{1}{3} \times 462=154 \mathrm{~cm}^{2}$
Now, total surface area - curved surface area $=2 \pi \mathrm{rh}+2 \pi \mathrm{r}^{2}-2 \pi \mathrm{rh}$
$\Rightarrow \Rightarrow 462-154=2 \pi r^{2}$
$\Rightarrow 308=2 \times \frac{22}{7} \times r^{2}$
$\Rightarrow r^{2}=\frac{308 \times 7}{44}=49$
$\Rightarrow r=7 \mathrm{~cm}$
Now, curved surface area = 154 cm2
$\Rightarrow 2 \pi r h=154$
$\Rightarrow 2 \times \frac{22}{7} \times 7 \times h=154$
$\Rightarrow h=\frac{154}{44}=3.5 \mathrm{~cm}$
$\therefore$ Volume of the cylinder $=\pi r^{2} h$
$=\frac{22}{7} \times 7^{2} \times 3.5$
$=539 \mathrm{~cm}^{3}$
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