Question

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

Answer 1

Answer:

Ratio of radius of two cylinder, r1:r2 = 2:3

Ratio of their heights, h1:h2 = 5:3

= r1/r2 = 2/3 h1/h2 = 5/3

so, Curved surface area of cylinder1 / curved surface area of cylinder2

= 2πr1h1 / 2πr2h2

= (2 × 22/7 × 2 × 5) / (2 × 22/7 × 3 × 3) = 10/9

∴ Ratio of their curved surface area is 10:9

Answer 2

Answer:

ratio of curved surface area = rh/ RH

rh/ RH = 2x × 5y/3x × 3y

rh/ RH = 2x × 5y/3x × 3y = 10xy / 9xy

rh/ RH = 2x × 5y/3x × 3y = 10xy / 9xy = 10 / 9

hence , ratio of curved surface area = 10 : 9