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. True
• B. False
• C. $\frac{3}{20}$
• D. $\frac{9}{20}$

Answer 1

The correct option is D $\frac{9}{20}$

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}.

$P\left(E\right)=\frac{n\left(E\right)}{n\left(S\right)}=\frac{9}{20}$