Tickets numbered 1 to 24 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 4?

Question: Tickets numbered 1 to 24 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 4?

Solution:
Here, S = {1, 2, 3, 4, ...., 23, 24}
Let E = event of getting a multiple of 3 or 4
= {3, 4, 6, 8, 9, 12, 15, 16, 18, 20, 21, 24}

∴P(E) = n(E)/n(S)
= 12/24
= 1/2