A chemist has 3 different acidic solutions.
The first solution contains 20% acid, the second contains 35% acid, the third contains 80% acid.
She created 54 liters of a 50% acid mixture, using all 3 solutions. The number of liters of 80% solution used is 2 times the number 35% solution is used
The chemist used_ liters of 20% solution,_35% of solution,_liters of 80% solution.