### 20 litres of a mixture contains milk and water in the ratio 3 : 1. Then the amount of milk to be added to the mixture so as to have milk and water in ratio 4 : 1 is-

A. 7 litres B. 4 litres C. 5 litres D. 6 litres Answer: Option C

### Solution(By Apex Team)

\begin{aligned}&\text{In 20 litres of mixture}\\ &\text{Quantity of milk}\\ &\Rightarrow\frac{3}{4}\times20=15\text{ litres }\\ &\text{Quantity of water}\\ &\Rightarrow\frac{1}{4}\times20=5\text{ litres }\end{aligned} Let the quantity of milk added be x litres. According to the question, \begin{aligned}&\Rightarrow\frac{15+x}{5}=\frac{4}{1}\\ &\Rightarrow15+x=4\times5\\ &\Rightarrow x=20-15\\ &\Rightarrow x=5\text{ litres }\end{aligned}

## 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