Question

Find the probability that a number selected from the number 1 to 25 is not a prime number

Answer 1

Prime numbers from 1 to 25= {2,3,5,7,11,13,17,19,23}

P(prime)= 9/25

Thus P(not prime)= 1-9/25= 16/25

Answer 2

Possible prime numbers - 2,3,5,7,11,13,17,19,23 (9 possibility)

sample space - 25

P(not prime no) = 25-9 / 25 = 16 /25