A mixture of 45 liters of milk and water contains 20% water. How many liters of water should be added to make it a 25% water solution? Options 5 3 2 4

Let's solve the problem step by step.

1. Determine the amount of water in the initial mixture:

   • The mixture is 45 liters and contains 20% water.
   • Amount of water = 20% of 45 liters = 0.20 * 45 = 9 liters.

2. Determine the amount of milk in the initial mixture:

   • Since the total mixture is 45 liters and it contains 9 liters of water, the amount of milk is:
   • Amount of milk = 45 liters - 9 liters = 36 liters.

3. Let $x$ be the amount of water to be added:

   • After adding $x$ liters of water, the total amount of water will be $9 + x$ liters.
   • The total volume of the mixture will be $45 + x$ liters.

4. Set up the equation for the new concentration of water:

   • We want the new mixture to be 25% water.
   • Therefore, $\frac{9 + x}{45 + x} = 0.25$.

5. Solve the equation: $\frac{9 + x}{45 + x} = 0.25$ $9 + x = 0.25(45 + x)$ $9 + x = 11.25 + 0.25x$ $9 + x - 0.25x = 11.25$ $0.75x = 2.25$ $x = \frac{2.25}{0.75}$ $x = 3$

So, the amount of water that should be added to make the solution 25% water is 3 liters.

Answer: 3