City water which is slightly chlorinated is being used to flush a tank of heavily chlorinated water The concentration C C t of the chlorine in the tank t hours after flushing begins is given by the following formula C 0 3 2 76e 0 35t C milligrams per gallon a What is the initial concentration of chlorine in the tank mg gal b Express the concentration of chlorine in the tank after 8 hours using functional notation Calculate the concentration of chlorine in the tank after 8 hours Round your answer to two decimal places mg gal