Tickets numbered from 1 to 21 are mixed and then a ticket is selected randomly. What is the probability that the selected ticket bears a number which is a multiple of 3?  Select the correct option:
A) 1/3
B) 2/5
C) 3/10
D) 3/7
E) 1/7
Here, S = [1, 2, 3, 4, …., 19, 20, 21]   Let E = event of getting a multiple of 3 = [3, 6, 9, 12, 15, 18, 21]   P (E) = n (E) / n (S) = 7 / 21 = 1/3   The answer is 1/3.
<result>A</result>
Tickets numbered from 1 to 21 are mixed and then a ticket is selected randomly. What is the probability that the selected ticket bears a number which is a multiple of 3?