Suppose that you have a supply of a 25% solution of alcohol and a 75% solution of alcohol. How many quarts of each should be mixed to produce 90 quarts that is 60% alcohol?

Thank you,and how did you get come up with the equation?

Thank you,and how did set up the equation?

If you let x be the amount of 25% solution, then .25x is the amount of alcohol in that solutions.

Since there are 90 qts in all, 90-x is the amount of the 75% solution. .75(90-x) is the amount of alcohol in that solution.

Add up the two amounts of alcohol, and it must equal the amount of alcohol in 90 qts of 60% solution.

Ta-daa

Thanks

To solve this problem, we can use a method called a mixture problem.

Let's denote the amount of 25% alcohol solution as x (in quarts) and the amount of 75% alcohol solution as y (in quarts).

Since the total amount of the mixture is 90 quarts, we have the equation:
x + y = 90

We also know that the resulting mixture should be 60% alcohol. The amount of alcohol in the 25% solution is 0.25x, and the amount of alcohol in the 75% solution is 0.75y.

Therefore, the equation for the total amount of alcohol in the mixture is:
0.25x + 0.75y = 0.6 * 90

Simplifying the equation:
0.25x + 0.75y = 54

Now we have a system of two equations:
x + y = 90
0.25x + 0.75y = 54

To solve this system, we can use substitution or elimination.

Let's use the substitution method:
From the first equation, solve for x:
x = 90 - y

Substitute this value of x into the second equation:
0.25(90-y) + 0.75y = 54

Distribute:
22.5 - 0.25y + 0.75y = 54

Combine like terms:
0.5y = 31.5

Divide by 0.5:
y = 63

Now substitute this value of y back into the first equation to find x:
x + 63 = 90
x = 90 - 63
x = 27

Therefore, you would need 27 quarts of the 25% alcohol solution and 63 quarts of the 75% alcohol solution to produce 90 quarts of a 60% alcohol mixture.

work with the amount of alcohol in each part. It has to add up to the total alcohol.

.25x + .75(90-x) = .60(90)
x = 27

so, 27 qt @ 25% and 63 qt @ 75%