# The radii of two right circular cylinders are in the ratio 2:3 and their heights are in the ratio 5:4 . Calculate the ratio of their curved surface areas.

Solution:  Let the radii of the cylinders  be 2r and 3r respectively , and their heights be 5h and 4h respectively .

Let  $S_{1}$  and $S_{2}$  be the curved surface area of two cylinders . Then ,

$S_{1}$  $=$ Curved surface area of the cylinder of height 5h and radius 2r .

$\Rightarrow$              $S_{1}= 2\pi \times 2r \times 5h= 20\pi rh$

$S_{2}=$ Curved surface area of the cylinder of height 4h and radius 3r .

$\Rightarrow$                $S_{2}=$ $2\pi \times 3r \times 4h =24\pi rh$

$\therefore$                $\frac{S_{1}}{S_{2}}= \frac{20\pi rh}{24\pi rh}=\frac{{5}}{6}\Rightarrow S_{1}:S_{2}=5:6$

## Most Viewed Questions

### Preparation Products

##### Knockout JEE Main (Six Month Subscription)

- AI Coach Study Modules, - Unlimited Mock Tests, - Study Improvement Plan.

₹ 9999/- ₹ 8499/-
##### Knockout JEE Main (Nine Month Subscription)

- AI Coach Study Modules, - Unlimited Mock Tests, - Study Improvement Plan.

₹ 13999/- ₹ 12499/-
##### Knockout NEET (Six Month Subscription)

- AI Coach Study Modules, - Unlimited Mock Tests, - Study Improvement Plan.

₹ 9999/- ₹ 8499/-
##### Knockout NEET (Nine Month Subscription)

- AI Coach Study Modules, - Unlimited Mock Tests, - Study Improvement Plan.

₹ 13999/- ₹ 12499/-