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?

• A. 1/2
• B. 2/5
• C. 8/15
• D. 9/20

Answer 1

The correct option is D 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}.
$\therefore p\left(E\right)=\frac{n\left(E\right)}{n\left(S\right)}=\frac{9}{20}$