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.
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.
Sudhanshu said:
9 years ago
Initial7 : 5
Final 7 : 9
Change is of mixture B by 4 unit I.e of 9 litre.
So, 1 unit = 9/4,
16 unit =16 * (9/4) = 36 change is happening in final value of 9 + 7 = 16,
Initial A = 7 * 36/12 = 21 (7+5=12).
So A =21, B = 15.
Final 7 : 9
Change is of mixture B by 4 unit I.e of 9 litre.
So, 1 unit = 9/4,
16 unit =16 * (9/4) = 36 change is happening in final value of 9 + 7 = 16,
Initial A = 7 * 36/12 = 21 (7+5=12).
So A =21, B = 15.
Hemanta said:
9 years ago
Thank Prabhas.
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?
Shiv Raj said:
9 years ago
Thanks for your explanation @Prabhas.
Vijay padala said:
9 years ago
Good explanation, thanks to all.
Bharti said:
9 years ago
I like the your answer @Vini.
Prakash said:
9 years ago
Hi, guys can anyone explain me from where 7x - 7/12 x 9 this fraction come?
Gopika S S said:
9 years ago
Thanks @Srividhya, your explanation is much better.
Keerthana said:
9 years ago
9 x 7 = 63 how you got 81@Silu.
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