A sewage treatment plant processes raw sewage to produce usable fertilizer and clean water
by removing all other contaminants. The process is such that each hour 12% of remaining
contaminants in a processing tank are removed. What percentage of the sewage would
remain after 1 day? How long would it take to lower the amount of sewage by half? How
long until the level of sewage is down to 10% of the original level?