A 180-litre mixture contains milk and water in the ratio 7 : 3. How many litres of water must be added to make the ratio 3 : 2?

💡 Solution & Explanation

Milk = 180 × 7/10 = 126 litres and water = 54 litres. Adding water does not change the milk. For milk : water = 3 : 2, the water must be 126 × 2/3 = 84 litres. So add 84 − 54 = 30 litres of water.