Question

One antifreeze solution is 20% alcohol. Another antifreeze solution is 12% alcohol. How many liters of each solution should be combined to make 15 liters of antifreeze that is 18% alcohol?

Answer 1

Can you help @RadEn

Answer 2

Can you help @CalebBeavers

Answer 3

Im thinking one equation would be

.20x+.12y=.18*15

and then one for the total amount
x+y=15

now you have two simultaneous equations

Answer 4

Let x = the amount of liters of the 20% alcohol solution
Let y = the amount of liters of the 12% alcohol solution

Then the total amount of liters of antifreeze is
x + y = 15

The total percentage of alcohol solution in the combined solution is
.20x + .15y = 2.7

Answer 5

Now conduct the following steps:

1. Multiply the first equation by .20
2. Subtract the second equation from the first
3. Solve for y
4. Then solve for x

Answer 6

Thank you @CalebBeavers and @Hero!!