Question

The radii of two cylinders are in the ratio 1:3 and their heights are in the ratio 3:2. What is the ratio of their curved surface areas?

Answer 1

Ratio = C.S.A. of 1st Cylinder / C.S.A of 2nd Cylinder

Ratio = 2×π×x×3y / 2×π×3x×2y

Ratio = 3xy / 6xy

Ratio = 3/6

Ratio = 1:2

Answer 2

Answer

CSA1 =CSA2

πr²3h=π(3r)²2h

r²3h=9r²*2h

3r²h=18r²h

3=18

∴1:6