A cylinder with height and radius `2:1` is filled with soft drink and then it is tilted so as to allow some soft drink to flow off to an extent where the level of soft drink just touches the lowest point of the upper mouth. If `2.1` L of soft drink is retained in the cylinder, what is the capacity of the cylinder ?

Explanation

Let radius of cylinder ` = r`

`:.` Height of cylinder `= 2r`

When cylinder is tilted, then the liquid retained in cylinder ` = (pir^2h)/2 = pir^3 = 2.1`

Now, Capacity of cylinder `V = pir^2h = 2pir^3`

`:.V = 2*pir^3 = 2**2.1 = 4.2 L`