Bunuel wrote:
virupaksh2010 wrote:
Eight litres are drawn off from a vessel full of water and substituted by pure milk. Again eight litres of the mixture are drawn off and substituted by pure milk.If the vessel now contains water and milk in the ratio 9:40, find the capacity of the vessel.
Possible AnswersSelected Possible Answer
A. 21 litrers
B. 22 litres
C. 20 litres
D. 14 litres
E. 28 litres
Possible AnswersSelected Possible Answer
A. 21 litrers
B. 22 litres
C. 20 litres
D. 14 litres
E. 28 litres
Let the capacity of the vessel be x.
After the first removal there would be x-8 liters of water left in the vessel. Note that the share of the water would be \frac{x-8}{x};
After the second removal, the removed mixture of 8 liters will contain 8*\frac{x-8}{x} liters of water, so there will be x-8-8*\frac{x-8}{x}=\frac{(x-8)^2}{x} liters of water left.
As the ratio of water to milk after that is \frac{9}{40}, then the ratio of water to the capacity of the vessel would be \frac{9}{40+9}=\frac{9}{49}.
So \frac{\frac{(x-8)^2}{x}}{x}=\frac{9}{49} --> \frac{(x-8)^2}{x^2}=\frac{9}{49} --> \frac{x-8}{x}=\frac{3}{7} --> x=14.
Answer: D.
if we are removing 8 litres of mixture,does that mean we are removing water share ?? because in mixture,how can we remove water now,as it contains milk too now. why do we use 8*water share??Pls clarify..