..:: Probability on Arithmetic Aptitude related Questions and Answers

Probability on Arithmetic Aptitude related Questions and Answers

Question : 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?

1. (1/2)
2. (2/5)
3. (8/15)
4. (9/20)
Answer : 4 - (9/20)

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.
TeamOne Monday, 28 November 2016