Question

A number is selected at random from the numbers 1 to 30. What is the probability that the selected number is a prime number?

Options

• `2/3`

• `1/6`

• `1/3`

• `11/30`

Answer 1

`bb(1/3)`

Explanation:

Total number of outcomes = 30.

Prime numbers in 1 to 30 are 2, 3, 5, 7, 11, 13, 17, 19, 23 and 29.

Number of favourable outcomes = 10.

∴ P(getting a prime number) = `("Number of favourable outcomes")/"Number of all possible outcomes"`

`=10/30 = 1/3`

Thus, the probability that the selected number is a prime number is `1/3`.