Question

The probability for a randomly selected number out of 1, 2, 3, 4, ..., 25 to be a composite number is ______.

पर्याय

• `15/25`

• `10/25`

• `11/25`

• `9/25`

Answer 1

The probability for a randomly selected number out of 1, 2, 3, 4, ..., 25 to be a composite number is `underlinebb(15/25)`.

Explanation:

Total outcomes:

S = {1, 2, 3, ..., 25}

n(S) = 25

Identifying Prime numbers and 1:

Primes between 1 and 25: 2, 3, 5, 7, 11, 13, 17, 19, 23 (Total 9 numbers)

Number 1 is neither prime nor composite.

Composite numbers:

Total composite numbers = Total numbers – (Prime numbers + 1)

n(E) = 25 – (9 + 1)

n(E) = 25 – 10

n(E) = 15

Probability:

`P(E) = (n(E))/(n(S))`

`P(E) = 15/25`