Problem
A particular professor is known for his arbitrary grading policies. Each paper receives a grade from the set {A, A-, B+. B, B-, C+}, with equal probability, independent of other papers. How many papers do you expect to hand in before you receive each possible grade at least once?
The response should include a reference list. Double-space, using Times New Roman 12 pnt font, one-inch margins, and APA style of writing and citations.