Aptitude - Alligation or Mixture - Discussion

Suppose 1 litre is 1rs.
Then 0.5 litres is 0.5 right.

x litres cost x rupee,
So gain = ((s.p-c.p)/c.p)*100;
So he actually sells it for 1 rupee as 1 litre of milk but he has less than 1 litre of milk, say x,
So x litres cost x rupee,
So 25=((1-x)/x)*100;,
x=4/5;,
So water is 1/5 which is 20%,

Hope it helps.

Formula is; (R/R+100)*100 So, ( 25/25+100)*100=20%.

let 100 litres of milk costs ---> x rs.

Now, they say how much water needs to be added to milk, we shall get 25 % gain
so,
100 lit milk+ y litres water costs --> x + 25 * X/100.

re-arranging the above equations

100 lit --> x rs.
100 lit + y litres water ---> x + 0.25x (adding the gain).

Cross multiply.

(x+0.25x) * 100 = 100*x + y*x.
solving we get;
25x = x * y.

y = 25 litres of water.

So now total mixture ( 100 lit milk + 25 lit of water ) = 125 lit of mixture.
to find out the percentage of water in 125 litres.

25*100/125 = 20 litre of water.

The solution is;

Water/milk * 100 is the formula for solving this.

Initially, water is 25% so remaining milk is 75% which makes W:M=1:4.
%water = w/total*100 and %milk= m/total*100 so %water = 1/5*100 = 20%.

Is 25% gain means he must have added 25% of water. So if 100lts of milk is there then you have 25lts of water. So part of solution which is water is 25/125. Then convert this into percentage.

I am unable to understand. Please, anybody explain me clearly.

x liters of milk ------- re.1.
(x+y) liters of mixture -------- re.1.25 where y is for water.
(x+y)/x = 1.25/1.
y/x = 1/4.

y = 1/5 * 100 = 20%.

CP of milk = X.
SP of Milk = X.

He did not get any profit so he mixed some water and sold it. Then he got a profit of 25%
SP of mixture=1.25X.

1.25X = X + 0.25X.
x = milk and 0.25X = water.
we need to calculate how much water is there in the mixture.
0.25X/1.25X = 0.2.
---->20% water.

If we apply alligation on % profit i.e. if he sell the milk at CP, he gains 0% and if he sell water at CP, he gains 100%. Thus by rule of alligation the ratio comes out to be 3:1.

& in that case % water in mixture becomes 25%. Now, by solving it by the method given and the method used by me, I m getting confused what is the perfect answer. Can anyone help?

Let 1 lt milk price is rs1 and x lt water mixed.
Then CP of (1-x)lt milk is rs(1-x) and SP is rs 1.
So, x/ (1-x) = 25% implies X= 20%.