A man and his wife appear in an interview for two vacancies in the same post. The probability of husband's selection is (1/7) and the probability Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5? of wife's selection is (1/5). What is the probability that only one of them is selected ? Choose the correct option.
A) 9/19 B) 9/20 C) 11/21 D) 11/23 E) 12
Here, S = {1, 2, 3, 4, ...., 19, 20}.   Let E = event of getting a multiple of 3 or 5 = {3, 6 , 9, 12, 15, 18, 5, 10, 20}.   P(E) = n(E)/n(S) = 9/20.   9/20)
<result>B</result>
A man and his wife appear in an interview for two vacancies in the same post. The probability of husband's selection is (1/7) and the probability Tickets numbered 1 to 20 are mixed up and then a ticket is drawn at random. What is the probability that the ticket drawn has a number which is a multiple of 3 or 5? of wife's selection is (1/5). What is the probability that only one of them is selected ?