In The Chocolate War, who was the treasurer of the chocolate sale, and how did he get the job?
Brian Cochran is the treasurer of the chocolate sale. He is good with numbers and can be trusted to fall in line with Brother Leon's wishes.
A senior, not "exactly a hotshot in the psychology department," who is volunteered by Brother Leon to be treasurer of the chocolate sale, a job which he performs with clerical efficiency.
Cochran's willingness to go along with Brother Leon can also be seen as an openness to intimidation. This is important because Leon has taken a big risk with this year's chocolate sale (an illegal risk). Leon has bought more chocolates than usual, using the school's money to do so, without getting necessary approval. Cochran knows this.
This quality in Cochran, along with his ability with numbers, explains why he is chosen to be treasurer for the chocolate sale.