Question

the radii of two cylinder are in ratio 2:3 and their heights are in the ratio 5:3 calculate the ratio of their curved surface areas

Answer 1

Hey there!

Ratio to their heights = 5 : 3

Ratio to their radius = 2 : 3

Height of 1st cylinder = 5x

Height of the 2nd cylinder = 3x

Radius pf the first cylinder = 2x

Radius of second cylinder = 3x

The formula for the curved surface area = ( 2 ) ( pie ) ( radius ) ( height )

The curved surface area of the 1st cylinder = ( 2 ) ( pie ) ( 2x ) ( 5x )

The curved surface area of the 2nd cylinder = ( 2 ) ( pie ) ( 3x ) ( 3x )

1st cylinder = ( pie ) ( 20x²)

2nd cylinder = ( pie ) ( 18x²)

Ratio = ( 20x² × pie ) ÷ ( 18x² × pie )

Ratio = 20x² ÷ 18x²

Ratio = 20 ÷ 18

Ratio = 10 ÷ 9

Ratio of curved surface area = 10 : 9

Hope my answer helps!

#BeBrainly

@sid071

Answer 2

Step-by-step explanation:

Let the radius of first cylinder be 2x

Let the radius of second cylinder be 3x

Let the height of first cylinder be 5x

Let the height of second cylinder be 3x

C.S.A of first cylinder = 2πrh

• 2π × 2x × 5y
• 20π xy

C.S.A of second cylinder = 2πrh

• 2π × 3x × 3y
• 18π xy

Ratio of their C.S.A's,

• 20π xy : 18π xy
• 20 : 18
• 10 : 9

∴ Ratio of their curved surface area is 10 : 9