"Many credit card companies target entering college freshmen with attractive interest rates. What they do not emphasize, however, is that the low rate will be in effect for only a short time, changing automatically to a much higher rate, often in just a few months. Freshman Michael Bronson accepts a credit card offer at %8 annual interest on any unpaid charges. The rate will increase to 15% annually after 6 months. To furnish his dorm room, he charges a small refrigerator, some bedding, and personal supplies amounting to $457.80. When he receives his first month's bill, he finds that he can pay just a minimum amount of $87.50. a) If Michael pays the minumum amount and makes no additional charges, how much will he owe the following month. (answer: 372.77) b) Suppose Michael continues to pay the same minimum amount for 4 more months. What will he owe at the end of the next month.(answer:26.94) c) The minumum amount normally is reduced as the total charge is reduced. Suppose each month, the minumum is reduced by $15 and Michael continues to pay only the minumum. can be pay off the charges in 6 months? If not, what will he owe at the end of 6 months? (answer: no, 166.45) This from the book Mathematics with Applications by Lial/Hungerford. First of all I cannot understand the parts "at %8 annual interest on any unpaid charges." and "When he receives his first month's bill, he finds that he can pay just a minumum amount of $87.50". What do these parts refer to ? I am not a native English speaker and I do not know these concepts very well. I have search for the solution on the internet but have found nothing. My approach for question part a is 457.80-87.50=370.300 but the answer is 372.27 Thank you.