A chemist needs 12 liters of a 10% alcohol solution but has only a 30% alcohol solution.

Question

How many liters each of the 30% solution and water should he mix to make the desired 12 liters of a 10% solution?

Answer 1

Let's have

x = # of liters of the 30% solution and

y = # of liters of water

Now, we know that the total # of liters needs to be 12, so we know

x + y = 12

We also know that if we add up the alcohol in x and the alcohol in y, we need to get the 10% alcohol of the 12 liters. We can write this in equation form:

0.3*x + 0.0*y = 0.1*12

Now that we have two equations and two variables, we can solve the system of equations and find x and y. Hope this helps!