A certain club has 10 members, including Jarry. One of the 10 members is chosen at random to be the president, one of the remaining 9 members is to be chosen at random to be the secretary, and one of the remaining 8 members is to be chosen at random to be the treasurer. What is the probability that Jarry will be either the member chose to be secretary or the member chose to be treasurer? Choose one:
A) 1 / 720
B) 1 / 80
C) 1 / 10
D) 1 / 9
E) 1 / 5

Rationale: in order to become a secretary the person can not be chosen as a president . this can be done in 9 / 10 ways . then to become a secretary this person ' s probability is 1 / 9 probability to become a secretary = ( 9 / 10 * 1 / 9 ) = 1 / 10 similar concept for treasurer . probability of not president = 9 / 10 , probability of not secretary = 8 / 9 , probability of treasurer 1 / 8 probability to become a treasurer = ( 9 / 10 * 8 / 9 * 1 / 8 ) = 1 / 10 since , the problem is saying jarry secretary or treasurer it is addition : 1 / 10 + 1 / 10 = 1 / 5 = e
Answer: E