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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:
Answer & Solution
Correct Answer:
Option
C
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. $$\left( {\frac{{100}}{{125}} \times 1} \right)$$ = $$\frac{4}{5}$$
By the rule of alligation, we have:
∴ Ratio of milk to water = $$\frac{4}{5}$$ : $$\frac{1}{5}$$ = 4 : 1
Hence, percentage of water in the mixture = $$\left( {\frac{1}{5} \times 100} \right)$$ % = 20%
Then, S.P. of 1 litre of mixture = Rs. 1, Gain = 25%
C.P. of 1 litre mixture = Rs. $$\left( {\frac{{100}}{{125}} \times 1} \right)$$ = $$\frac{4}{5}$$
By the rule of alligation, we have:
∴ Ratio of milk to water = $$\frac{4}{5}$$ : $$\frac{1}{5}$$ = 4 : 1
Hence, percentage of water in the mixture = $$\left( {\frac{1}{5} \times 100} \right)$$ % = 20%
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LoginLet's assume milkman has 100 liter of milk, If he added x liter of water, the percentage of water in the mixture=(100+x)x×100
The milk gain 25%, he must have added 25 liter water in 100 liter of milk. Then the percentage of water in the mixture=(100+25)25×100=20%
In the new mixture, If the milk is 80% then 80% of total mixture should be 100 liter
(100+x)×10080=100
8x=200
x=25
Then, the percentage of water in the mixture =(100+25)25×100=20%