$6 \mathrm{fl}$. oz. of a saline solution was mixed with $2 \mathrm{fl}$. oz. of pure water to make a $45 \%$ saline solution. Find the percent concentration of the first solution.
Solution
Step 1 :Let the percent concentration of the first solution be x. Set up the equation: \(6x + 2(0) = 8(0.45)\)