Aptitude - Alligation or Mixture - Discussion
Discussion Forum : Alligation or Mixture - General Questions (Q.No. 8)
8.
A container contains 40 litres of milk. From this container 4 litres of milk was taken out and replaced by water. This process was repeated further two times. How much milk is now contained by the container?
Answer: Option
Explanation:
| Amount of milk left after 3 operations = |  |
40 |  |
1 - | 4 |  |
3 |  litres |
| 40 |
| = | |
40 x | 9 | x | 9 | x | 9 | |
= 29.16 litres. |
| 10 | 10 | 10 |
Discussion:
67 comments Page 2 of 7.
Jitender said:
9 years ago
Simple: in question given he replace milk with water three times. Once he replaces then further repeat process two times.
40 litre milk ----> 4 litre milk removed (4 is 10% of 40) = 36 litre left.
Now again 4 litre milk removed (again 10% removed) from 36 litre mean 3.6 litre removed = 32.4 litre left.
Now again 4 litre removed = mean 10% of 32.4 is 3.24 so 3.24 litre remove and you left with 29.16 litre!
40 litre milk ----> 4 litre milk removed (4 is 10% of 40) = 36 litre left.
Now again 4 litre milk removed (again 10% removed) from 36 litre mean 3.6 litre removed = 32.4 litre left.
Now again 4 litre removed = mean 10% of 32.4 is 3.24 so 3.24 litre remove and you left with 29.16 litre!
(1)
Arun Kumar said:
4 years ago
In the first step, 4 litres of milk is taken out from 40 litres it means 4/40=0.1.
It shows that every time 0.1 times the available milk is taken out so in the next step there will be 36 litres of milk. 36 * 0.1=3.6 litres is removed in the second step.
Now, 32.4 litres of milk is remaining in the mixture. Again 32.4 * 0.1=3.24 litres is removed in the third step. Now 29.16 litres of milk is remaining.
It shows that every time 0.1 times the available milk is taken out so in the next step there will be 36 litres of milk. 36 * 0.1=3.6 litres is removed in the second step.
Now, 32.4 litres of milk is remaining in the mixture. Again 32.4 * 0.1=3.24 litres is removed in the third step. Now 29.16 litres of milk is remaining.
(27)
Jaivene said:
9 years ago
Given 40L milk.
Step1: 4L milk is replaced & 4L water is added, i.e. it now contains 40L mix of 36L M & 4L W in d ratio 9:1,
So even if you take 1L of the mix it will contain (9parts M & 1 part W) & this is repeated 2mor times.
So to calculate the amount of milk present :
1st time: 40 * 9/ (9 + 1 =10).
2nd time: 40 * (9/10) * (9/10), 3rd time: 40 * (9/10) * (9/10) * (9/10) = 29.16.
Step1: 4L milk is replaced & 4L water is added, i.e. it now contains 40L mix of 36L M & 4L W in d ratio 9:1,
So even if you take 1L of the mix it will contain (9parts M & 1 part W) & this is repeated 2mor times.
So to calculate the amount of milk present :
1st time: 40 * 9/ (9 + 1 =10).
2nd time: 40 * (9/10) * (9/10), 3rd time: 40 * (9/10) * (9/10) * (9/10) = 29.16.
Sam said:
1 decade ago
40-4 == 36.
Now mixture contain 36 part milk and 4 part water.
36-4 = 32.
But all 4 part is not milk, it is mixture of water and milk.
In 4 part amount of water was=4*4/40=1*4/10=0.4.
So now milk = 32+0.4 = 32.4.
Process repeats one more time as follows:
Milk = 32.4-4 = 28.4.
This 4 is mixture of water and milk.
Water in this 4 lit is = 7.6*4/40 = 0.76.
So finally milk = 28.4+0.76 = 29.16.
Now mixture contain 36 part milk and 4 part water.
36-4 = 32.
But all 4 part is not milk, it is mixture of water and milk.
In 4 part amount of water was=4*4/40=1*4/10=0.4.
So now milk = 32+0.4 = 32.4.
Process repeats one more time as follows:
Milk = 32.4-4 = 28.4.
This 4 is mixture of water and milk.
Water in this 4 lit is = 7.6*4/40 = 0.76.
So finally milk = 28.4+0.76 = 29.16.
Cosul said:
7 years ago
Very well explained @Akshay Aswati.
The logic here is whenever something is taken out,
As Now, the basic principle is that;
When you remove any amount of the mixture, it removes both the liquids in the same ratio as the mixture itself.
Hence for the second time and third time we are using 4/40*4 for milk and 36/40 *4 water
and 32.4 /40 *4 for milk (29.16) and 8/40 *4 for water.
The logic here is whenever something is taken out,
As Now, the basic principle is that;
When you remove any amount of the mixture, it removes both the liquids in the same ratio as the mixture itself.
Hence for the second time and third time we are using 4/40*4 for milk and 36/40 *4 water
and 32.4 /40 *4 for milk (29.16) and 8/40 *4 for water.
GSDau said:
4 years ago
40-litre juice and 0 litre water.
removed 4-litre juices and replace water.
36 litre juice +4 water we get a mixture of 40 litre.
again 4 litre juices remover it means removing mixture,
this 4 litre contain 36liter juice:4 LITER WATER,
36/36+4*4==3.6 litre juices remove.
40==36-3.6=32.2.
4-litre mixture removes we get 32.4:7.6.
32.4/32.4 + 7.6*4==3.24.
32.4-3.24==29.16.
removed 4-litre juices and replace water.
36 litre juice +4 water we get a mixture of 40 litre.
again 4 litre juices remover it means removing mixture,
this 4 litre contain 36liter juice:4 LITER WATER,
36/36+4*4==3.6 litre juices remove.
40==36-3.6=32.2.
4-litre mixture removes we get 32.4:7.6.
32.4/32.4 + 7.6*4==3.24.
32.4-3.24==29.16.
(5)
Ajay said:
1 decade ago
40 lit milk.
4 lit taken out.
36 lit milk and 4 lit water.
Again 4 lit mixture remove from total mixture.
4/ (total mixture = 40) --- 1 eqn.
36*4/40 = 3.6 milk and 4*4/40 = 0.4 water are remove.
Remaining milk = 32.4 (36-3.6) and water = 7.6 (8-0.4) lit.
Again same process as equation (1).
32.40-3.24 = 29.16 lit milk remains in mixture.
Simplest approach. !
4 lit taken out.
36 lit milk and 4 lit water.
Again 4 lit mixture remove from total mixture.
4/ (total mixture = 40) --- 1 eqn.
36*4/40 = 3.6 milk and 4*4/40 = 0.4 water are remove.
Remaining milk = 32.4 (36-3.6) and water = 7.6 (8-0.4) lit.
Again same process as equation (1).
32.40-3.24 = 29.16 lit milk remains in mixture.
Simplest approach. !
Tanuz said:
10 years ago
If you are taking out 4 liters out of a 40 liter solution and replacing it with water, you are effectively replacing 1/10th of the solution with water.
=> Fraction of milk will become (9/10) of the original.
If the process is repeated 'n' times, fraction of milk will become (9/10)^n of the original.
We are given the process was done thrice.
=> Fraction of milk will become (9/10) of the original.
If the process is repeated 'n' times, fraction of milk will become (9/10)^n of the original.
We are given the process was done thrice.
Parvy Govil said:
10 years ago
First extract & refill. 36l milk, 4l water.
Milk in solution = 9/10; water = 1/10.
2nd extract: 4l taken out.
Milk = 9/10*4 = 3.6 water taken out = 0.4.
Milk remaining = 32.4, water remaining = 7.6.
Milk in solution = 32.4/40; water in solution = 7.6/40.
3rd extract: Milk extracted = 4*81/100.
Milk left will be 32.4-3.24 = 29.16.
Milk in solution = 9/10; water = 1/10.
2nd extract: 4l taken out.
Milk = 9/10*4 = 3.6 water taken out = 0.4.
Milk remaining = 32.4, water remaining = 7.6.
Milk in solution = 32.4/40; water in solution = 7.6/40.
3rd extract: Milk extracted = 4*81/100.
Milk left will be 32.4-3.24 = 29.16.
Chauhan said:
2 years ago
First, when we took out 4 L of milk, and add 4 L of water, then the mixture become in a ratio of 9:1 then we were going to again checked checking, how much milk is present in the mixture 36 * 9/10 (9+1) = 32.4.
This is the new ratio of milk then we have to do it one more time32.4 * 9/10 = 29.16.
This is the new ratio of milk then we have to do it one more time32.4 * 9/10 = 29.16.
(4)
Post your comments here:
Quick links
Quantitative Aptitude
Verbal (English)
Reasoning
Programming
Interview
Placement Papers