Alligation or Mixture problems
A milkman buys milk at Rs 25 per litre and adds 1/4 of water to it and sells the mixture at Rs 26 per litre. His gain (in %) is?
Given mixture = 48 lit Milk in it = 48 x 5/8 = 30 lit => Water in it = 48 - 30 = 18 lit Let 'L' lit of water is added to make the ratio as 3:5 => 30/(18+L) = 3/5 => 150 = 54 + 3L => L = 32 lit.
Let C.P. of 1 litre milk be Re. 1. S.P. of 1 litre of mixture = Re.1, Gain = 50 %. 3 ∴ C.P. of 1 litre of mixture = ❨ 100 x 3 x 1 ❩ = 6 350 7 By the rule of alligation, we have: C.P. of 1 litre of water C.P. of 1 litre of milk 0 Mean PriceRe. 6 7 Re. 1 1 7 6 7 ∴ Ratio of water and milk = 1 : 6 = 1 : 6.
Ratio of milk and water = 2 : 1Quantity of milk = 60 X 2/3 = 40 litreQuantity of water = 20 litreTo make ratio, 1: 2, we have to double the water that of milkSo, water should be 80 litre.That means 80 ? 20 = 60 litre water to be added.