DRDO Multi tasking staff Model paper 7

Ratio of milk and water = 2 : 3 = 40 : 60
Given, 40% of the 2 : 3 solution of milk and water is replaced with water
⇒ Volume of milk removed = 40 × 40/100 = 16
⇒ Volume of water removed = 40 × 60/100 = 24
∴ new ratio of milk and water after removing 40% of solution = 24 : 36
New ratio of milk and water after adding 40% of water = 24 : 76
∴ % reduction in concentration = (40 - 24)/40 = 40%