Question

450 litres of a mixture of milk and water contain the milk and water in the ratio 9 : 1. How much water should be added to get a new mixture containing milk and water in the ratio 3 : 1?

• A. 54
• B. 90
• C. 45
• D. 63

Answer 1

The correct option is B 90

Quantity of milk in 450 L mixture=$\frac{9}{10}\times 450=405$
Quantity of water in 450 L mixture=$450-405=45$
Let x l water is added then
$\Rightarrow \frac{405}{45+x}=\frac{3}{1}$
$\Rightarrow 135+3x=405$
$\Rightarrow 3x=405-135$
$\Rightarrow 3x=270$
$\Rightarrow x=90$
Hence 90 litre water is added .