I have two solutions and I'm trying to

Question

I have 15 liters of a solution that is 5% alcohol and another solution that is 12% alcohol. How many liters of the 12% solution would I need to make an 8% solution of alcohol?

Answer 1

Let x = the amount of 12% alcohol solution

 

We can set up the following equation to express the total concentration of the mixture

 

15(0.05) + x(0.12) = (x + 15)(0.08)

 

In the previous step, we converted the percentages to decimals, and (x + 15) represents the amount of 8% alcohol solution

 

Now, let's simplify

 

0.75 + 0.12x = 0.08x + 1.2

 

0.75 + 0.04x = 1.2

 

0.04x = 0.45

 

x = 11.25 L of 12% alcohol solution