Aptitude - Alligation or Mixture - Discussion
Discussion Forum : Alligation or Mixture - General Questions (Q.No. 6)
6.
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:
4%
6
%
%20%
25%
Answer: Option
Explanation:
Let C.P. of 1 litre milk be Re. 1
Then, S.P. of 1 litre of mixture = Re. 1, Gain = 25%.
| C.P. of 1 litre mixture = Re. |  |
100 | x 1 |  |
= | 4 |
| 125 | 5 |
By the rule of alligation, we have:
| C.P. of 1 litre of milk C.P. of 1 litre of water | |||||
| Re. 1 | Mean Price
| 0 | |||
|
|
||||
 Ratio of milk to water = |
4 | : | 1 | = 4 : 1. |
| 5 | 5 |
| Hence, percentage of water in the mixture = | |
1 | x 100 | % |
= 20%. |
| 5 |
Discussion:
65 comments Page 7 of 7.
Neetu said:
1 decade ago
Then how we take 1/5 if we do 4/1= its become 4/5(4.. second become by 4+1=5) whay u take 1/5 plz explain me
Amir said:
1 decade ago
@amir:
"milk:water==100:x"
where x is gain%
Soln:
m:w==100:25==4:1
that means water percentage is=
1/5*100=20%
answer==20
"milk:water==100:x"
where x is gain%
Soln:
m:w==100:25==4:1
that means water percentage is=
1/5*100=20%
answer==20
Moncy said:
1 decade ago
@ Pankaj:
Its a formula for finding the C.P when the gain % is given.C.P=((100/(100+gain%))+selling price)
Its a formula for finding the C.P when the gain % is given.C.P=((100/(100+gain%))+selling price)
Rahul said:
1 decade ago
@ Pankaj:
The explanation states that the normal cost of milk is actually Re. 1. Now this dishonest milkman is buying some of that milk, adding some water and selling the new mixture for Re. 1 (when the actual value should be lower). So since he is selling the mixture at Re. 1, that becomes his selling price. This is because he has made a profit due to having used some water to dilute it. Now we need to figure out how much of the actual milk has gone into the final product and since water is free, the cost of the milk becomes the cost price.
So:
Cost price of milk + 25% profit = Selling price of milk mixture
Lets assume the cost price of milk is x.
x + 0.25x = 1.00 (since the selling price of mixture is 1 and the profit is 25% of cost price)
1.25x = 1.00
- we all hate decimals, so lets make it easier:
125x = 100
x = 100/125 = 4/5(thats where it comes from). Now that multiplication by 1 is really useless in this problem. Unless the problem, specifically states that he sold something like 10 liters, there is no need multiply by total liters sold. Then do alligation to figure out how much milk and how much water.
Hope that helps.
The explanation states that the normal cost of milk is actually Re. 1. Now this dishonest milkman is buying some of that milk, adding some water and selling the new mixture for Re. 1 (when the actual value should be lower). So since he is selling the mixture at Re. 1, that becomes his selling price. This is because he has made a profit due to having used some water to dilute it. Now we need to figure out how much of the actual milk has gone into the final product and since water is free, the cost of the milk becomes the cost price.
So:
Cost price of milk + 25% profit = Selling price of milk mixture
Lets assume the cost price of milk is x.
x + 0.25x = 1.00 (since the selling price of mixture is 1 and the profit is 25% of cost price)
1.25x = 1.00
- we all hate decimals, so lets make it easier:
125x = 100
x = 100/125 = 4/5(thats where it comes from). Now that multiplication by 1 is really useless in this problem. Unless the problem, specifically states that he sold something like 10 liters, there is no need multiply by total liters sold. Then do alligation to figure out how much milk and how much water.
Hope that helps.
(3)
Pankaj said:
1 decade ago
From where 100/125 is come ?
plz tell soon
plz tell soon
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