Question

There is a vessel whose 80% volume is filled with milk and water solution. The concentration of milk in the solution is 90%. Using a steel mug, one mug-full of solution is
withdrawn and replaced by an equal quantity of water. After 3 such replacements, the concentration of milk in the solution becomes 30.87%. What is the ratio of volumes of
the vessel and the steel mug?
25:6
24:5
27:7
20:6​

Answer 1

Answer: A vessel contains 80 liters of milk.

8 liters of milk is taken out from it and replaced by water.

Now Milk remains = 80 - 8 = 72 liters

Replaced with water Milk = 72 liters + 8 litres water ratio 72 : 8 = 9 : 1

Then again from mixture, 8 liters is again taken out and replaced by water.

Now the mixture had 9 : 1 milk water ratio, means in 10 litre mixture 9 litre milk and 1 litre water

From 8 litre mixture, milk taken out will be = 9/10 × 8 = 7.2 litres milk and 0.8 litre water

Now milk left in the mixture will be

= 72 litres - 7.2 litres = 64.8 litres milk

Water will be = 80 litres - 64.8 litres = 15.2 litres

The amount of milk in final mixture will be 64.8 litres milk with 15.2 litres added water.

Answer : the amount of milk in final mixture will be 64.8 litres milk

Step-by-step explanation: