Let radii be 2r and 3r and heights be 5h and 3h.
∴ Ratio of volumes = [π(2r)² x 5h] / [π(3r)² x 3h]

Correct Option: C

Let radii be 2r and 3r and heights be 5h and 3h.
∴ Ratio of volumes = [π(2r)² x 5h] / [π(3r)² x 3h]
= 20/27 = 20 : 27

Given that , 2πrh = 264
and πr²h = 924
∴ ( πr²h) / (2πrh) = 924 / 264 = 7/2
⇒ r/2 = 7/2
⇒ r = 7
∴ d = 2r = 14 m
Also, 2 x (22/7) x 7 x h = 264

Correct Option: A

Given that , 2πrh = 264
and πr²h = 924
∴ ( πr²h) / (2πrh) = 924 / 264 = 7/2
⇒ r/2 = 7/2
⇒ r = 7
∴ d = 2r = 14 m
Also, 2 x (22/7) x 7 x h = 264
⇒ h = 264 / 44 = 6
∴ d/h = 14/6 = 7/3 = 7 : 3

According to the formula,
Percentage change in volume is directly proportional to the height,

Correct Option: C

According to the formula,
Percentage change in volume is directly proportional to the height,
So percentage decrease in volume = 8%

According to the formula
Percentage increase in volume
= (2k + k²/100)% = ( 2 x 25 + 25²/100)%

Correct Option: A

According to the formula
Percentage increase in volume
= (2k + k²/100)% = ( 2 x 25 + 25²/100)%
= (50 + 625/100)% = (50 + 6.25)%
= 56.25%

Here, A = -8%, B = 4%
According to the formula,
Net effect on volume = [2A + B + A² + 2AB/100 + A²B/100²]%

Correct Option: A

Here, A = -8%, B = 4%
According to the formula,
Net effect on volume = [2A + B + A² + 2AB/100 + A²B/100²]%
= [2 x (-8) + 4 + (-8)² + 2 x (-8) x 4 /100 + (-8)² x 4 /100²]
= [-16 + 4 + 64 - 64/100 + 256/10⁴]%
=[-12 + 0 + 0.0256]%
= -11.9744% (decrease)