Question

In what ratio must water be mixed with milk to gain 16% on selling the mixture at cost price​

Answer 1

cost price of water = 0 ₹( because we get water free)

let CP of 1 L milk = 1 ₹

then SP of 1 L milk = 1 ₹

gain = 16%

when milk is mixed with water then Cost price of mixture = {100/(100+16)}×1 = 100/116 = 25/29

now apply mixture and allegation rule.

Now see the image

you will get 4:25