g106 wrote:
15 lts are taken of from a container full of liquid A and replaced with Liquid B. Again 15 more lts of the mixture is taken and replaced with liquid B. After this process, if the container contains Liquid A and B in the ratio 9:16,What is the capacity of the container?
A:45
B:25
C:37.5
D:36
E:42
working on formula (by karishma)
CiVi=CfVf
Let X be the volume of container then
here initial concentration is 100% and volume is (X-15)
final volume is again=x
so 1*(x-15)=Cf(x)
Cf=(x-15)/x
this process repeats again
here initial concentration is Cf= (x-15)/x and volume is (X-15)
final volume is again=x
{(x-15)/x}*(x-15)]=Cf1x
given Cf1=9/25
so [(x-15)/x]^2=9/25------>(x-15)/x=3/5
X=37.5
Ans C