A 200-litre mixture contains milk and water in the ratio 7 : 3. How many litres of water must be added to make the ratio 2 : 1?

💡 Solution & Explanation

Milk = 200 × 7/10 = 140 litres and water = 60 litres. Adding water does not change the milk. For milk : water = 2 : 1, the water must be 140 × 1/2 = 70 litres. So add 70 − 60 = 10 litres of water.