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?

Options

• `1/2`

• `2/5`

• `8/15`

• `9/20`

Answer 1

`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`