Aptitude - Alligation or Mixture - Discussion
Discussion Forum : Alligation or Mixture - General Questions (Q.No. 3)
3.
A can contains a mixture of two liquids A and B is the ratio 7 : 5. When 9 litres of mixture are drawn off and the can is filled with B, the ratio of A and B becomes 7 : 9. How many litres of liquid A was contained by the can initially?
Answer: Option
Explanation:
Suppose the can initially contains 7x and 5x of mixtures A and B respectively.
| Quantity of A in mixture left = |  |
7x - | 7 | x 9 |  |
litres = | |
7x - | 21 | litres. |
| 12 | 4 |
| Quantity of B in mixture left = | |
5x - | 5 | x 9 | |
litres = | |
5x - | 15 | litres. |
| 12 | 4 |
 |
|
= | 7 | |||||
|
9 |
 |
28x - 21 | = | 7 |
| 20x + 21 | 9 |
252x - 189 = 140x + 147
112x = 336
x = 3.
So, the can contained 21 litres of A.
Discussion:
100 comments Page 5 of 10.
Gurpreet said:
9 years ago
@ Prabhas, how is this possible?
Ager mixture which is replaced more than the addition of ration like 7 + 5 = 12 as mixture value which is replaced is 18 litre then?
Ager mixture which is replaced more than the addition of ration like 7 + 5 = 12 as mixture value which is replaced is 18 litre then?
Shashank Yadav said:
8 years ago
The simplest way to do this question:
A and B are in a ratio of 7:5, we can say that, A=7x. A should definitely be a multiple of 7 and hence 21 is the answer.
A and B are in a ratio of 7:5, we can say that, A=7x. A should definitely be a multiple of 7 and hence 21 is the answer.
Kalai said:
6 years ago
@Yamini.
Just simple initially there is 7:5 ratio of A & B now they need initial liters of A so in the answer which is a multiple of 7 is 21.
Simple one.
Just simple initially there is 7:5 ratio of A & B now they need initial liters of A so in the answer which is a multiple of 7 is 21.
Simple one.
(33)
Suri said:
8 years ago
The Whole Question is clear but Why we are Multiplying with 9 in ration (7/12) *9.
What does multiplying with 9 litres means?
Please answer thank you.
What does multiplying with 9 litres means?
Please answer thank you.
Akash said:
1 decade ago
So easy. The answer should be a multiple of 7 as the initial ratio of A:B is 7:5.
And only 21 is in the option which is a multiple of 7. So option C.
And only 21 is in the option which is a multiple of 7. So option C.
Lakshminarasimha said:
7 years ago
The total 9 drawn off ans filled.7:5,
3/4 parts drawnoff and filled,
For every 1part is 3 total 12 parts i.e 12*3=36,
7*3=21,5*3=15.
3/4 parts drawnoff and filled,
For every 1part is 3 total 12 parts i.e 12*3=36,
7*3=21,5*3=15.
Arjun said:
9 years ago
The formula is x*(1 - y/x )^n.
So 12 * (1 - 9/12)^1,
So the answer is 3.
Since we take 7x of A.
The answer is 7 * 3 = 21.
So 12 * (1 - 9/12)^1,
So the answer is 3.
Since we take 7x of A.
The answer is 7 * 3 = 21.
Rachana said:
6 years ago
@Kiran.
Because we have total mixture initially as 7+5=12.
And now as the ratio is 7:5.
i.e.
7/12 and 5/12 respectively!
Because we have total mixture initially as 7+5=12.
And now as the ratio is 7:5.
i.e.
7/12 and 5/12 respectively!
(2)
Prabhas said:
9 years ago
Assume 7 : 5 as 12 liters.
9 liters are drawn form the mixture.
So,
12 - 9 = 3.
Then,
7 * 3 = 21 and 5 * 3 = 15.
9 liters are drawn form the mixture.
So,
12 - 9 = 3.
Then,
7 * 3 = 21 and 5 * 3 = 15.
Aksh said:
7 years ago
It is said that the ratio initially is 7:5, so the quantity of first is a multiple of 7, so 21 is the answer.
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