In a 40 litre mixture of milk and water, the ratio of milk to water is 3 : 1. How much water (in litres) should be added to make this ratio 2 : 3?
Answer & explanation
Correct answer: option 3
Initial quantity of mixture = 40 litres
Initial ratio of milk to water = 3 : 1
Ratio of milk to water after adding milk = 2 : 3
Milk in mixture = (3/4) × 40 = 30
Water in mixture = 40 – 30 = 10
Let x litre water be added
New ratio of milk and water = 2 : 3
⇒ 30 : 10 + x = 2 : 3
⇒ 90 = 20 + 2x
⇒ x = 35