Aptitude - Alligation or Mixture - Discussion

1:2 is ratio now quantity of alcohol in it is 1/3 ok, now the question is asking about the quantity of whiskey that is 1-1/3 so we got 2/3 answer because 1/3which we got earlier is the part of alcohol now 2/3 is the part of whiskey replaced.

Let, the total original amount of whiskey = 10 ml, i.e. 4 ml alcohol and 6 ml non-alcohol.

Let x ml be the amount removed,
Total alcohol left = 4-0.4x.

New quantity of whiskey added = x ml out of which 0.19 is the alcohol.

Thus, the final quantity of alcohol,
= 4-0.4x+0.19x=4-0.21x.
ATQ, (4-0.21x)= 26% of 10 [Here, initially 10],
=> x = 20/3 ml.

As per the question, we need to find the x ml removed as a ratio of the initial volume,
= (20/3)/10 = 2/3 (Answer).

The ratio of 1st and 2nd quantities is=1:2 as it solved in explanation.
but they asked the quantity of whiskey replace means 2/(1+2)=2/3.

Can anyone explain me to get it clearly?

Consider 100L of Whiskey Mixture.
40L alcohol and 60L Water.

Let x be the amount of whiskey replaced in Litres. So 0.4x is the alcohol removed and 0.19x is the alcohol added. 26L is the new alcohol content.
We will do an alcohol balance.
40-0.4x+0.19x = 26 -----> x = 200/3.
x/100 = 2/3.

By using alligation method we can easily get the ratio in which they were mixed together.

So,
= (26-19) : (40-26),
= 7:14,
= 1:2.
So 1/3 of first and 2/3 of second are mixed to make the third mixture in which 26% alcohol is there;

Now the question is asking for the quantity which is removed or taken out from the first jar
If 1/3 of jar A is used to make a new mixture.
So, 2/3 of jar A is taken out or replaced.

@Rohan.

Thanks sir, it was so simple to understand.

@All.

Who is asking how did 2/3 come? Here is the explanation.

It is because the total we have now is 1+2 that is 3;. And 2 out of that is 2nd part hence 2/3 was replaced.

Wrong, the correct answer is;

19% whisky replaced be X portion of 1 jar, then 40% whisky is 1-X portion, and then mixture is 26%;

19/100 * X + 40/100 * (1-X) = 26/100 *1.
X = 7/13 of Jar.

Here, 1:2 is not mixture ratio.it's ratio between 1st mixture quantity after removal and 2nd added mixture quantity.

Here a word used same amount of mixture "replaced".

Mixture amount ratio = 1:2 means total mixture amount =3 part.

Added mixture amount = 2/3. Which was replaced.