Aptitude - Alligation or Mixture - Discussion

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.

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%.

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.

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

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.

Thank you all for explaining it.

Simple.

Gain=25.
Total milk =125.
Then 25/125=20%.

Suppose Milk man have 100 litre he want sell same 100 litre by adding some water.

Milk...................100 litre(initially)
Milk+ water.......100 litre(after addition of milk)
So, milk = 100-water.

Now, cost price Rs/-100.
Because of 25% profit selling price Rs/-125
100 * 100 = (100-water) * 125.
Water = 20.
Out of 100 litre water quantity is 20 litre.
So, answer is 20%.

Please someone help me.

How to find out the weight of the water mixed in gm per kilogram of milk?

Say the vendor buys L liters of milk and the cost of this is X.
Now, the vendor mixes some amount of water so the quantity is becoming say (L+Z) the cost of this is X(original cost)+25/100(X) that would be 5X/4.

Cost---->quantity
X---->L
5X/4--->?
So, ? = 5L/4,
So (L+Z) = 5L/4,
Z =L/4,

So, that would be 25% right but the answer is 20%.