Question

ratio of radius of two cylinders is 2:3 and ratio of their height is 5:3 then find ratio of their volumes___

a)27:20
b)20:27
c)9:4

please step by step...​

Answer 1

ratio of radius = 2 : 3

Let the height of Cylinder C1 be 2x and Cylinder C2 be 3x.

Similarly , Let height of Cylinder C1 be 5y and Cylinder C2 3y ( given ratio 5:3 )

☛ Volume of Cylinder = πr²h

➜ Volume of Cylinder C1 = π× (2x)² × 5y

➜ Volume of Cylinder C1 = 20πx²y ----(i)

☛ Volume of Cylinder C2 = πr²h

➜ Volume of Cylinder C2 = π × (3x)² × 3y

➜ Volume of Cylinder C2 = 27πx²y -----(ii)

➲ Ratio = Volume of Cylinder C1 / Volume of Clyinder C2

from (i) and (ii) ,

➜ Ratio = 20πx²y / 27πx²y

cancel πx²y

➜ Ratio = 20/27

Hence, The ratio of thier volumes is 20 : 27

So, Option (b) is correct.