A 30-litre mixture of milk and water contains 15% water. How much water must be added to it to increase the percentage of water in the solution to 37.5% ?
Answer & explanation
Correct answer: option 2
Given,
Total mixture = 30L
Water contains = 15% of 30 L = 4.50 L,
Milk contains = 85% of 30 L = 25.50 L
Now we add some water, then water contains in the mixture is 37.5% of the total mixture.
The ratio of milk and water in the final mixture = 62.5 : 37.5 = 5 : 3
Let us add x liters of water, so
\(\frac{25.50}{4.50 + x}\) = \(\frac{5}{3}\)
76.50 = 22.50 + 5x
5x = 54
x = 10.8 L
So the water added to the mixture is 10.8 liters.