The following is the score distribution for the first midterm with the
corresponding letter grades.

Score	Letter Grade	Number of Tests

59-60	A+		21
55-58	A		32
51-54	A-		27
48-50	B+		29
44-47	B		46
41-43	B-		34
38-40	C+		40
34-37	C		38
31-33	C-		31
28-30	D+		24
24-27	D		19
21-23	D-		15
0-20	F		27