Solve the Problem. -At a Plant That Packages Bottled Spring Water, the Water

Multiple Choice

Solve the problem.
-At a plant that packages bottled spring water, the water is passed through a sequence of ion-exchange filters to reduce the sodium content prior to bottling. Each filter removes 70% of the sodium present in the water passing through it. Determine the number of filters that must be used to reduce the sodium concentration from 30 parts-per-million to 7.20 parts-per-million.

A) 4 filters
B) 6 filters
C) 7 filters
D) 5 filters