Question

In a mixture of 40 litres, the ratio of milk: water is 4: 1. If some quantity of mixture is taken out and then 4 litres milk and 4 litres of water is added to the mixture, then the ratio of milk and water becomes 8: 3. Find the quantity of the mixture that was taken out.

• A. 10 litres
• B. 12 litres
• C. 15 litres
• D. 18 litres
• E. None of these

Answer 1

The correct option is C 15 litres

Quantity of milk and water inititally = 32 litres and 8 litres
Let the removed quantity be x
So, quantity of milk and water after removing x liters of the mixture $=32-\frac{4}{5}x\text{and}8-\frac{1}{5}x$
After adding 4 litres each of milk and water $=36-\frac{4}{5}\times x\text{and}12-\frac{1}{5}\times x$
Now, the ratio is $8:3\Rightarrow 3(36-0.8x)=8(12-0.2x)$Solving, we get x = 15 litres