ArithmeticMilk contains 5% water. What quantity of pure milk should be added to 10 liters of milk reduce this to 2%?

Milk contains 5% water. What quantity of pure milk should be added to 10 liters of milk reduce this to 2%?

A
5 L
B
1L
C
15L
D
None of these

Solution:

Initially $5 %$ is the portion of the water in the mixture, 95% is the portion of the milk in the mixture. So quantity of water in litres = 0.5 and also quality of milk in $10 L = \frac{95}{100} \times 10 = 9.5 L$

Let x be the a variety of pure milk to be added to the mixture to make water 2%.

$\frac{0.5}{9.5 + x} \times 100 = \frac{0.2}{9.8} \times 100 \Rightarrow 9.8 \times 0.5 = 0.2 (9.5 + x)$

$\Rightarrow x = 15$