It is. For my school, 90-100 is an A, 80-89 is a B, 70-79 is a C, 60-69 is a D, and 0-59 is an F. No pluses or minuses. The B was because of stupid mistakes on examinations, such as reading the question too fast and missing a key part of the problem (e.g. friction or no friction). I am fully...