Answer:
Tasha should mix 25 liters of 20% solution and 50 liters of 50%.
Step-by-step explanation:
Let x liters be the amount of 20% solution and y liters be the amount of 50% solution Tasha takes.
1. Tasha needs 75 liters of a 40% solution of alcohol. Then
x + y = 75
2. There are
- liters of alcohol in x l of 20% solution
- liters of alcohol in 50% solution
- liters of alcohol in 75 liters of 40% solution
In total, of alcohol that is 30 l, so
0.2x + 0.5y = 30
3. Solve the system of two equations:
From the first equation:
Substitute it into the second equation
Tasha should mix 25 liters of 20% solution and 50 liters of 50%.