### A dishonest milkman professes to sell his milk at cost price but he mixes it with water and thereby gains 25%. The percentage of water in the mixture is:

A. 4% B. 16% C. 20% D. 25% Answer: Option C

### Solution(By Apex Team)

Let C.P. of 1 litre milk be Rs. 1 Then, S.P. of 1 litre of mixture = Rs. 1, Gain = 25% C.P. of 1 litre mixture = Rs. $\left(\frac{100}{125}\times1\right)=\frac{4}{5}$ By the rule of alligation, we have: ∴ Ratio of milk to water = $\Large\frac{4}{5}: \frac{1}{5}$ = 4 : 1 Hence, percentage of water in the mixture = $\left(\frac{1}{5} \times 100\right) \%$ = 20%

## 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