Algebra word problem but done without system of equations I have this word problem, its well known mixture type of problem, I can solve this using a system of equations, so that is not the issue. But is it possible to solve this just using numerical ways, such as ratio-proportion method. Here is the problem: > An 18% brine solution is a salt water mixture which has 18% salt. Bobby mixed some 18% brine solution with some 35% brine solution to make 85 L of 19% brine solution. What is the volume in liters of the 35% brine solution. I have found another similar like problem here on stackoverflow: solve ratio word problem without algebra SO just to give an idea of the approach.

$85\; L$ of a $19\%$ brine solution has $0.19 \times 85 = 16.15\; L$ of salt. If Bobby just used the $18\%$ solution he would have $0.18 \times 85 = 15.30\; L$ of salt. So he needed an additional $16.15 - 15.30 = 0.85\; L$ of salt. If you replace $1\; L$ of $18\%$ solution with $1\; L$ of $35\%$ solution you get an additional $0.35 - 0.18 = 0.17\; L$ of salt. So we have to do that $0.85/0.17 = 5$ times. Thus Bobby must have used $80\; L$ of $18\%$ and $5\; L$ of $35\%$ solution.