Answer:
19 gallons of 25% alcohol and 1 gallon of 5% alcohol
Explanation:
If x is the gallons of 25% alcohol, and y is the gallons of 5% alcohol, then:
x + y = 20
0.25x + 0.05y = 0.24(20)
Solve the system of equations using substitution:
0.25x + 0.05(20 − x) = 0.24(20)
0.25x + 1 − 0.05x = 4.8
0.2x = 3.8
x = 19
y = 20 − x
y = 1
You need 19 gallons of 25% alcohol and 1 gallon of 5% alcohol.