In what ratio of water be mixed with milk to gain 16 ²/ ₃ % on selling the mixture at cost price?

Let the price per kg of mixed variety be Rs. P;
then By the rule of alligation,
Now, (20 - P) / (P - 15) = (2 / 3)
? 60 ? 3P = 2P ? 30
? 5P = 90
? P = Rs. 18

Let capacity of the container be P liter; then
P(1 ? 1/3)⁴ = 16
? P (2 / 3)⁴ = 16
? P(16 / 81) = 16 liters
? P = 81 liters

Average no. of legs per head = (320 / 100) = (16 / 5)
or, 3 : 2
No. of goats = (3 / 3 + 2) × 100 = 60
No. of chickens = 100 ? 60 = 40.

Total quantity of iron = 4 (1 / 4) + 6 (2 / 3) = 1 + 4 = 5 kg.
Total quantity of tin = (4 + 6) ? 5 = 5 kg.
In the resultant mixture, iron : tin = 5 : 5 or 1 : 1

As per figure we can calculate the ration as below
Number of officers / Number of workers = 1000 / 7000 = 1 / 7
No. of officers = 1 / (1 + 7) × 400 = 50
No. of workers = 400 ? 50 = 350

Here , Ratio of milk and water in mixture of 60 litre = 2 : 1
? Quantity of milk = 2y = 40 litre
Quantity of water = y = 20 litre
If ratio of milk and water is to be 1 : 2, then in 40 litres of milk, water should be 80 litre
? Quantity of water to be added = 60 litre.

Using the Alligation method ,
Here , C₁ = 160 paise , C₂ = 145 paise and Mean cost Price ( M ) = 154 paise
Required ratio = ( M - C₂ ) : ( C₁ - M )
? (Dearer wheat) : (Cheaper wheat) = 9 : 6
Hence , (Dearer wheat) : (Cheaper wheat) = 3 : 2