Question

• The ratio of surface area of a sphere and curved surface
area of a hemisphere is 9:2. Find ratio of their volumes.

Pls answer fast
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Answer 1

Answer:

The answer is 2:1

Step-by-step explanation:

thae ratio of their volumes is 4:2 which is reduced to 2:1

Answer 2

the ratio of surface area of a sphere and curved surface area of a hemisphere is 9:2 Then ratio of their volumes ​= 27:4

Step-by-step explanation:

surface area of a sphere =  4πR₁²

curved surface area of a hemisphere =  2πR₂²

surface area of a sphere/curved surface area of a hemisphere = 4πR₁²/2πR₂²

= 2R₁²/R₂²

2R₁²/R₂² = 9/2

=> R₁²/R₂² = 9/4

=> R₁²/R₂² = 3²/2²

=> R₁/R₂ = 3/2

Volume of sphere = (4/3)πR₁³

Volume of Hemisphere = (2/3)πR₂³

Volume of sphere /Volume of Hemisphere  = ((4/3)πR₁³)/((2/3)πR₂³)

= 2 (R₁/R₂)³

= 2 (3/2)³

= 27/4

Ratio of their volumes is 29 : 7