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 3 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.
Dhivya said:
8 years ago
Initial A:B 7:5 ->12Parts.
New ratio A:B 7:9.
In the new ratio only 4 parts is changed so, 4parts=9litre.
for 12 parts =27litre + 9Litre.
Initial Litre is 36.
for Initial liquid A :7/12 *36 = 21Litre.
New ratio A:B 7:9.
In the new ratio only 4 parts is changed so, 4parts=9litre.
for 12 parts =27litre + 9Litre.
Initial Litre is 36.
for Initial liquid A :7/12 *36 = 21Litre.
BDSHAHJAHAN said:
8 years ago
Good job @Silu, @Anilkumar.
Karen said:
8 years ago
Do we use the ratio? Please tell.
Keerthana said:
9 years ago
9 x 7 = 63 how you got 81@Silu.
Kia said:
8 years ago
Let A initially be 7x & B be 5x.
The amount of A in a mixture is 7x /12& the amount of B in a mixture is 5x/12.
Let the total amount of mixture be x.
Now, it is given that 9litre of the mixture is taken out from the mixture & it can fill up with an amount of B.
Now, amount of new mixture be-
The Amount of A is 7(x-9)/12.
The amount of Bis 5(x-9)/12+9.
Now, it is given that the resultant ratio is 7/9.
7(X-9)/12:5(x-9)/12+9 = 7/9.
Now, it can easily solve to get the value of x=36 which is put in 7x/12 then get the amount of A is 21.
The amount of A in a mixture is 7x /12& the amount of B in a mixture is 5x/12.
Let the total amount of mixture be x.
Now, it is given that 9litre of the mixture is taken out from the mixture & it can fill up with an amount of B.
Now, amount of new mixture be-
The Amount of A is 7(x-9)/12.
The amount of Bis 5(x-9)/12+9.
Now, it is given that the resultant ratio is 7/9.
7(X-9)/12:5(x-9)/12+9 = 7/9.
Now, it can easily solve to get the value of x=36 which is put in 7x/12 then get the amount of A is 21.
ESWARARAO S said:
8 years ago
When mixture removed, same 7:9 remains.
7 : 5 when Mixture B,
Gained 3 points of B mixture for 9 litres.
So 1 Point of mixture is 3 litres,
And, 7 Points of A mixture is 7 * 3= 21 litres.
7 : 5 when Mixture B,
Gained 3 points of B mixture for 9 litres.
So 1 Point of mixture is 3 litres,
And, 7 Points of A mixture is 7 * 3= 21 litres.
Teju said:
9 years ago
7x+5x-9 = 9x(mixture removed equals B added)
X = 3
7x = 21= A.
X = 3
7x = 21= A.
Prakash said:
9 years ago
Hi, guys can anyone explain me from where 7x - 7/12 x 9 this fraction come?
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.
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers