The content in the beakers A and B are 90 litres of milk and 90 litres of water respectively .Now 30 litres of milk is taken from A and put in to the beaker B after throughly mixing 12 litres of mixure is taken from B and put in to the beaker A.what is the percentage of water in beaker A?

The ratio of milk to water in beaker B after mixing 30 litres of milk from beaker A to beaker = 30: 90 = 1: 3

The remaining quantity of milk in beaker = 90 - 30 = 60 litres

Quantity of milk in beaker A when 12 litres of mixture from beaker B is mixed in beaker = $$60 + 12\frac{1}{4}$$ = 60 + 3 = 63 litres

Quantity of water in beaker A when 12 litres of mixture from beaker B is mixed in beaker = $$12\frac{3}{4}$$ = 9 litres

Total quantity of mixture in beaker A = 63 + 9 = 72 litres

Required percent = $$\frac{9}{72} * 100$$ = 12.5%