Aptitude - Alligation or Mixture - Discussion
Discussion Forum : Alligation or Mixture - General Questions (Q.No. 4)
4.
A milk vendor has 2 cans of milk. The first contains 25% water and the rest milk. The second contains 50% water. How much milk should he mix from each of the containers so as to get 12 litres of milk such that the ratio of water to milk is 3 : 5?
Answer: Option
Explanation:
Let the cost of 1 litre milk be Re. 1
| Milk in 1 litre mix. in 1st can = | 3 | litre, C.P. of 1 litre mix. in 1st can Re. | 3 |
| 4 | 4 |
| Milk in 1 litre mix. in 2nd can = | 1 | litre, C.P. of 1 litre mix. in 2nd can Re. | 1 |
| 2 | 2 |
| Milk in 1 litre of final mix. = | 5 | litre, Mean price = Re. | 5 |
| 8 | 8 |
By the rule of alligation, we have:
| C.P. of 1 litre mixture in 1st can C.P. of 1 litre mixture in 2nd can | ||||||||
|
Mean Price
|
|
||||||
|
|
|||||||
 Ratio of two mixtures = |
1 | : | 1 | = 1 : 1. |
| 8 | 8 |
| So, quantity of mixture taken from each can = |  |
1 | x 12 |  |
= 6 litres. |
| 2 |
Discussion:
74 comments Page 3 of 8.
Dhanwin said:
1 decade ago
Different approach:
==============
Can 1 ---- 25% water + 75% milk.
Ratio ---- 1:3 (25/75 = 1/3).
Can 2 ---- 50% water + 50% milk.
Ratio ----- 1:1 (50/50 = 1/1).
If I take p liters from can 1 and q liters from can 2.
So that total should be 12 liters with water : milk = 3 : 5.
So I get following equation.
P+q/3p+q = 3/5 -------- (equation 1).
Now try checking the given options in questions and the answer should be the "option" which satisfies the (equation 1).
Ex:
Let p = 6 and q = 6.
Then 6+6/(3*6+6) = 3/5.
So the equation 1 is satisfied. So the answer is 6 liters from can 1 and 6 liters from can 2.
Other options given won't satisfy the (equation 1).
==============
Can 1 ---- 25% water + 75% milk.
Ratio ---- 1:3 (25/75 = 1/3).
Can 2 ---- 50% water + 50% milk.
Ratio ----- 1:1 (50/50 = 1/1).
If I take p liters from can 1 and q liters from can 2.
So that total should be 12 liters with water : milk = 3 : 5.
So I get following equation.
P+q/3p+q = 3/5 -------- (equation 1).
Now try checking the given options in questions and the answer should be the "option" which satisfies the (equation 1).
Ex:
Let p = 6 and q = 6.
Then 6+6/(3*6+6) = 3/5.
So the equation 1 is satisfied. So the answer is 6 liters from can 1 and 6 liters from can 2.
Other options given won't satisfy the (equation 1).
Dhruv Sahni said:
1 decade ago
Container A has 25% water, Container B has 50% of water and after mixing these two final mixture has 3/8 -> 37.5% of water.
So by allegation method the ratio of A and B in final mixture will be 25% 50% 37.5%.
50%-37.5% : 37.5%-25%.
= 12.5% = 12.5% = 1:1.
So Ratio of A:B in final mixture is 1:1, hence in 12 liter of mixture there will be 6L of A and 6L of B.
So by allegation method the ratio of A and B in final mixture will be 25% 50% 37.5%.
50%-37.5% : 37.5%-25%.
= 12.5% = 12.5% = 1:1.
So Ratio of A:B in final mixture is 1:1, hence in 12 liter of mixture there will be 6L of A and 6L of B.
Anu said:
10 years ago
Please somebody clarify the logic behind that question in short way.
Megh said:
10 years ago
Can any one tell me how did you get 5/8?
Shashi bhushan said:
10 years ago
Let x and y liters from the can to be mixed to make 12 liters of milk.
Can 1 has x/4 (water) and 3x/4 (milk).
Can 2 has y/2 (water) and y/2 (milk).
So new ratio of water to milk is.
(x/3+y/2)/(3x/4+y/2) = 3/5.....(1).
By the question.
x+y = 12.....(2).
To solve these equation.
x = 6, y = 6.
Can 1 has x/4 (water) and 3x/4 (milk).
Can 2 has y/2 (water) and y/2 (milk).
So new ratio of water to milk is.
(x/3+y/2)/(3x/4+y/2) = 3/5.....(1).
By the question.
x+y = 12.....(2).
To solve these equation.
x = 6, y = 6.
Parvy Govil said:
10 years ago
Let x litres of A and y litres of B is extracted x+y = 12.
Milk quantity = 1/5x+1/2y = 3/5(4/5x+1/2 y).
x = 5 litres.
y = 7 litres.
Milk quantity = 1/5x+1/2y = 3/5(4/5x+1/2 y).
x = 5 litres.
y = 7 litres.
Ramakrishna said:
10 years ago
In 1st 25% water, 2nd 50% water.
Then resultant ratio given that 3:5, if 3+5 is 100% then 3 is 37.5% water.
That is subtracted from 37.5-25 = 50-37.5 = 12.5.
Then those two values are same so ratio is 1:1 answer 6 lit, 6 lit.
If you do for milk also get same answer.
Then resultant ratio given that 3:5, if 3+5 is 100% then 3 is 37.5% water.
That is subtracted from 37.5-25 = 50-37.5 = 12.5.
Then those two values are same so ratio is 1:1 answer 6 lit, 6 lit.
If you do for milk also get same answer.
Soumya said:
10 years ago
If a chemical solution contains 30% water & 70% Alkali. What quantity of water should be added to 6 liter of solution. So that water content become 40%.
Stalin said:
9 years ago
Can any explain how did we get 5/8?
Bakhtiar said:
9 years ago
Can anyone help me to understand this problem?
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