Question

The radii of two cylinder are in the ratio $3:2$ and their heights are in the ratio $4:5$. Calculate the ratio of their curved surface areas.

Answer 1

$\frac{r_1}{r_2}=\frac{3}{2}$ & $\frac{h_1}{h_2}=\frac{4}{5}$

$\frac{(CSA{)}_1}{(CSA{)}_2}=\frac{2\pi r_1{h}_1}{2\pi r_2{h}_2}=\left(\frac{r_1}{r_2}\right)\left(\frac{h_1}{h_2}\right)=\frac{3}{2}\times \frac{4}{5}=\frac{6}{5}$.