Question

The radius of the cylinder are in the ratio 2:3 and height 5:3 calculate of the ratio of their curved surface area

Answer 1

r1 : r2 = 2 : 3
r1/r2= 2/3
h2:h2=5/3

C.S 1 : C .S 2 = 2πr1h1 : 2πr2h2
= 2πr1h1 / 2πr2h2
= r1/r2 × h1/ h2
= 2/3 × 5/3
=10/ 9

Answer 2

hello users ....


solution:-
we know that:
curved surface area = 2πrh

Here,
according to given :
Ratio between their radii 2 : 3 
let Radius of first cylinder = 2r
And
let Radius of second cylinder = 3r

Also,
The ratio between their height 5 : 3
let the height of first cylinder = 5h
And
let height of second cylinder = 3h

now,
C.S.Area of first cylinder = 2πrh
= 2π×(2r)×5h
= 20 × πrh

And
C.S.Area of second cylinder. = 2πrh
= 2π×(3r) × 3h
= 18 × πrh

Now,
required Ratio = C.S.Area of first cylinder / C.S.Area of second cylinder

= 20πrh / 18πrh

= 20 / 18

= 10/9
=> 10 : 9 Answer

⭐ hope it helps ⭐