TS ICET 23 May 2018 Shift 1 Paper

Let the outer and inner radius of the cylinder be R and r respectively.
Given the height of cylinder h = 7 and the difference between outer and inner surface area $=44\mathit{c}{\mathit{m}}^2$
$\Rightarrow 2\mathit{\pi }\mathit{R}\mathit{h}-2\mathit{\pi }\mathit{r}\mathit{h}=44$
$\Rightarrow \mathit{R}-\mathit{r}=\frac{44}{2\mathit{\pi }\mathit{h}}=1\mathit{c}\mathit{m}$
The thickness of the cylinder $=\mathit{R}-\mathit{r}=1\mathit{c}\mathit{m}$