Free GMAT Test Questions

All industrial effluents generated in the town of Dombeyville are released into the river that flows through the town. The medium and large industries in the town account for 75 percent of these industrial effluents. To reduce the amount of toxic materials in the town's industrial effluents by 75 percent in the next five years, the town council has mandated all the medium and large industries in the town to set up their own effluent treatment plants within five years so that they release effluents only after chemically removing all toxic materials.

The town council's plan to reduce the amount of toxic materials released into the river by 75 percent makes which of the following assumptions?