Question

A mixture of 85 kg contains milk and water in the ratio 27 : 7. how much more water is to be addedto get a new mixture containing milk and water in the ratio 3:1?

Answer 1

Volume of mixture = 85 kg
Milk. Water
67.5 kg. 17.5
67.5 kg. 17.5+ X

let X kg water must added so the ratio becomes 3:1
$\frac{67.5}{17.5 + x} = \frac{3}{1} \\ 67.5 = 52.5 + 3x \\ 3x = 15 \\ x = 5$
so the amount of water should be added is 5 kg.