The radii of the bases of two cylinders are in the ratio 3 : 5 and their heights are in the ratio 2 : 3. Find the ratio of their curved surface areas.

Explanation

Ratio `=frac{2 pi r_{1} h_{1}}{2 pi r_{2} h_{2}}=(frac{r_{1}}{r_{2}}) times(frac{h_{1}}{h_{2}}) `

`
=frac{3}{5} times frac{2}{3}=frac{2}{5}=2: 5`