Question: An industry is required to clean up 4.0 t of a by-product containing both toxic and inert material. The toxic content is 15%; the rest is inert. The by-product is treated with 45 t of solvent resulting in an amount of dirty solvent containing 0.35% toxic material and a discard containing 1.2% toxic material, some solvent, and all the inert materials. Determine the amount of dirty solvent produced, the percentage of solvent in the discard, and the percentage of toxic substance removed in the discard.