Final answer:
To solve this problem, we can use the concept of the weighted average. Let's denote the number of liters of the 11% alcohol solution as 'x' and the number of liters of the 20% alcohol solution as 'y'. Based on the given information, we can set up the equation 0.11x + 0.20y = 0.13(x + y). Solving this equation, we find that the number of liters of the 3% solution needed is the same as the number of liters of the 11% solution.
Step-by-step explanation:
To solve this problem, we can use the concept of the weighted average. Let's denote the number of liters of the 11% alcohol solution as 'x' and the number of liters of the 20% alcohol solution as 'y'.
Based on the given information, we can set up the following equation:
0.11x + 0.20y = 0.13(x + y)
Next, we can solve this equation to find the value of x:
- Expand the equation: 0.11x + 0.20y = 0.13x + 0.13y
- Combine like terms on both sides: 0.02y = 0.02x
- Divide both sides by 0.02:
- y = x
So, in order to get the desired 13% solution, the number of liters of the 3% solution needed would be the same as the number of liters of the 11% solution, which is 'x'.