A mixture of 150 liters of wine and water contains 20% water. How much more water should be added so that water becomes 25% of the new mixture?

Given:

• Total mixture = 150 liters
• Water is 20% of the mixture → Water = 20% of 150 = 30 liters
• Wine = 150 - 30 = 120 liters
• We want water to be 25% of the new mixture

Let x = liters of water to be added

Then, new water = 30 + x

New total mixture = 150 + x

We want:

(30 + x) / (150 + x) = 25/100 = 1/4

Step 1: Cross-multiply:

4(30 + x) = 150 + x
=> 120 + 4x = 150 + x
=> 3x = 30
=> x = 10

Answer: 10 liters of water should be added.