Question

Nature can play a large role in removing pollution from the environment. For example, oil-eating microbes were used to help clean up the 2010 oil spill in the Gulf of Mexico C. Suppose that ten tons of pollutants are dumped into a bay, and that microbes remove 20% of the pollutants in the bay each day. Let an denote the number of tons of pollutants in the bay on day n. That is, ai 10, a2 = 10(0.8) and so on. (a) Find expressions for a3 and 24. Do not simplify your answers. The sequence {an} is a geometric sequence. (b) What is the first term of the sequence? What is the common ratio between terms? (c) Find a formula for the general term an. (d) Find lim an. Give a reason for your answer. n->

Answer 1