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 ?
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 ?
A. 1/2
B. 2/5
C. 8/12
D. 9/20
Answer : D. 9/20…
Explanation:
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
