In a mixture of milk and water the proportion of water by weight was 75%. If in 60 gm of mixture 15 gm water was added, what would be the percentage of water? (Weight in gm)

Given:

• Initial mixture = 60 gm
• Water percentage in the mixture = 75%
• So, water in the mixture = 75% of 60 = (75/100) × 60 = 45 gm
• Milk in the mixture = 60 - 45 = 15 gm
• Additional water added = 15 gm

New total water = 45 + 15 = 60 gm
Total weight of new mixture = 60 + 15 = 75 gm

New percentage of water = (60 / 75) × 100 = 80%

Answer: 80%