# Duk Son wants to mix 20% saline solution with a 12% saline solution to make 40 ounces of a solution that is 15% saline. how many ounces of the 12% saline solution will he need?

##### 1 Answer

#### Answer:

He will need

#### Explanation:

If we denote:

Then the conditions of the task lead to the following equations:

Now we can write the system of equations to solve:

I started calculations with multiplying second equation by

Now we can multiply first equation by

After adding both equations we get:

Now we can calculate

So the solution of the system of equations is:

The answer is: We need