Aptitude - Alligation or Mixture - Discussion
Discussion Forum : Alligation or Mixture - General Questions (Q.No. 1)
1.
A vessel is filled with liquid, 3 parts of which are water and 5 parts syrup. How much of the mixture must be drawn off and replaced with water so that the mixture may be half water and half syrup?
Answer: Option
Explanation:
Suppose the vessel initially contains 8 litres of liquid.
Let x litres of this liquid be replaced with water.
| Quantity of water in new mixture = |  |
3 - | 3x | + x |  |
litres |
| 8 |
| Quantity of syrup in new mixture = | |
5 - | 5x | |
litres |
| 8 |
 |
|
3 - | 3x | + x | |
= | |
5 - | 5x | |
| 8 | 8 |
5x + 24 = 40 - 5x
10x = 16
| x = |
8 | . |
| 5 |
| So, part of the mixture replaced = | |
8 | x | 1 | |
= | 1 | . |
| 5 | 8 | 5 |
Discussion:
198 comments Page 10 of 20.
Abd said:
9 years ago
8/5 * 1/8 is done because part of the mixture has to be replaced.
Since a part of the mixture is 1/8, the final answer is multiplied with it.
Since a part of the mixture is 1/8, the final answer is multiplied with it.
Muni said:
9 years ago
Hi.
People who didn't understand why the answer is 1/5 and not 8/5.
It's because of twist in question.
They asked what part of the total mixture.
3 part water + 5 part liquid = 8.
Assume 8 liter is the total mixture.
We got 8/5 liter now see what 8/5 liter percentage in 8 liters.
Ie (8/5) / 8.
= 8/5 * 1/8.
= 1/5.
Trick is in question. So in options they didn't mention units because its a const.
Thank you.
People who didn't understand why the answer is 1/5 and not 8/5.
It's because of twist in question.
They asked what part of the total mixture.
3 part water + 5 part liquid = 8.
Assume 8 liter is the total mixture.
We got 8/5 liter now see what 8/5 liter percentage in 8 liters.
Ie (8/5) / 8.
= 8/5 * 1/8.
= 1/5.
Trick is in question. So in options they didn't mention units because its a const.
Thank you.
Disha said:
9 years ago
How came 5x + 24 = 40 - 5x?
C.h.udhay said:
9 years ago
Superb @Kiran.
ANURAG SRIVASTAVA said:
9 years ago
Let us assume there is total 80 liter of mixture I take 80 for easy division of water and syrup you can take any number or x. So mixture contains 3 part water and 5 part syrup mean there is total 8 part.
8 part is 80.
So 1 part will be 80/8 = 10 litre.
Water is 3 part=30 litre.
Syrup is 5 part=50 litre.
Let why litre of syrup is taken out and replace with water for an equal proportion of water and syrup.
Then the quantity of water = quantity of syrup.
30 + y = 50 - y.
By solving y =10 litre this quantity is taken out form syrup 50 litre.
So this is how many parts of syrup. It is 10/50 = 1/5 part since the answer is in part according to question 1/5th part of syrup should take out and replace by water. You can solve accordingly above with x litre instead of 80litre but x can confuse so always take numerical value for easy calculation. Thanks, I hope it is understandable.
8 part is 80.
So 1 part will be 80/8 = 10 litre.
Water is 3 part=30 litre.
Syrup is 5 part=50 litre.
Let why litre of syrup is taken out and replace with water for an equal proportion of water and syrup.
Then the quantity of water = quantity of syrup.
30 + y = 50 - y.
By solving y =10 litre this quantity is taken out form syrup 50 litre.
So this is how many parts of syrup. It is 10/50 = 1/5 part since the answer is in part according to question 1/5th part of syrup should take out and replace by water. You can solve accordingly above with x litre instead of 80litre but x can confuse so always take numerical value for easy calculation. Thanks, I hope it is understandable.
(1)
Rajnish jha said:
9 years ago
New quantity of syrup = 5x - 5y.
New quantity of water = 3x - 3y + 8y = 3x + 5y.
They are equal to each other.
=> 5x - 5y = 3x + 5y.
=> 2x = 10y.
=> y/x = 2/10 = 1/5.
=> 8y/8x = 1/5.
New quantity of water = 3x - 3y + 8y = 3x + 5y.
They are equal to each other.
=> 5x - 5y = 3x + 5y.
=> 2x = 10y.
=> y/x = 2/10 = 1/5.
=> 8y/8x = 1/5.
Prakash said:
9 years ago
Please, anyone solve it in alligation formula.
Sundar said:
9 years ago
You guys all great. Knowing how to solve a problem in an easy way is great and explaining to others is a bigger than that. Great helping kind. Once again Thank you all.
Jomson joy said:
9 years ago
Thanks, vicllusion. It is the simple method.
Sandeep said:
9 years ago
Anyone, please clear my doubt.
How (3 - 3x / 8 + x) = 5x + 24?
How (3 - 3x / 8 + x) = 5x + 24?
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