AMC 10 2000 Problem 14

Mrs.Walter gave an exam in a mathematics class of five students. She entered the scores in random order into a spreadsheet, which recalculated the class average after each score was entered. Mrs. Walter noticed that after each score was entered, the average was always an integer. The scores (listed in ascending order) were 71,76,80,82, and 91 . What was the last scores Mrs.Walter entered?

Answer Choices
A. 71
B. 76
C. 80
D. 82
E. 91