### In 80 litres mixture of milk and water the ratio of amount of milk to that of amount of water is 7 : 3. In order to make this ratio 2 : 1, how many litres of water should be added ?

A. 5 litres B. 6 litres C. 8 litres D. 4 litres Answer: Option D

### Solution(By Apex Team)

$\begin{array}{l}\text{Quantity of milk}\\ =\frac{7}{10}\times80=56\text{ litres }\\ \text{ Quantity of water }\\ =\frac{3}{10}\times80=24\text{ litres }\\ \text{Let x litre water be added}\\ \text{Then,}\\ \Large\frac{56}{24+x}=\frac{2}{1}\\ \text{⇒ 24 + x = 28}\\ \text{So, }\text{x = 4 litres}\end{array}$

## Related Questions On Alligation

A. 2 : 5
B. 3 : 5
C. 5 : 3
D. 5 : 2

### An alloy contains zinc, copper and tin in the ratio 2 : 3 : 1 and another contains copper, tin and lead in the ratio 5 : 4 : 3. If equal weights of both alloys are melted together to form a third alloy, then the weight of lead per kg in new alloy will be:

A. $\large\frac{1}{2} \mathrm{~kg}$
B. $\large\frac{1}{8} \mathrm{~kg}$
C. $\large\frac{3}{14} \mathrm{~kg}$
D. $\large\frac{7}{9} \mathrm{~kg}$

A. 81 litres
B. 71 litres
C. 56 litres
D. 50 litres