A pond initially contains 8 million gallons of fresh water. Water containing an
undesirable chemical flows into the pond at the rate of 2 million gallons per year and the mixture
in the pond flows out at the same rate. The concentration of chemical in the incoming water is
increasing in time t according to the expression 0:02t grams per gallon.
Find the formula describing the amount of chemicals (in grams) as a function of time (in years)
and use it to determine the amount of chemical in the pond after 5 years.