Grade Puzzle

Grade Puzzle
The teacher has finished grading the math papers at High School. The class size is under 30. One third of the class got a 'B', one fourth got a 'B-' and one sixth got a 'C'. One eighth of the class flunked and the remainder of the class received an 'A'.
.
How many students in the class received an 'A' ?
.
.
Ans: 3
.
.
Exp:
Class size is below 30. Below 30 a numbr that can have 1/4 1/6 1/3 and 1/8th is only 24. So the class size is 24. 1/3 got B means 8 stdnts. 1/4 got B- means 6 stdnts. 1/6 got C means 4 stdnts. 1/8 flunkd means 3 stdnts. Remaining 3 got A.