The probability that number selected at random from the number 1, 2, 3, 4, 5, 6, 7, 8, ..., 100 is a prime, is

Question

The probability that number selected at random from the number 1, 2, 3, 4, 5, 6, 7, 8, ..., 100 is a prime, is (A)  0.4  (B)  0.25  (C)  0.45  (D)  0.43

Tardigrade Admin · Accepted Answer

Let E = event of getting prime numbers from 1 to 100 = 2,3,5,7,11,13,17,19,23,29,31,37,41,43,47, 49, 53,59,61,71,73,79,83,89,97 ∴ | n(E)=25 ∴ Required probability =(25/100)=0.25

Q. The probability that number selected at random from the number $1, 2, 3, 4, 5, 6, 7, 8, ..., 100$ is a prime, is

$0.4$

$0.25$

$0.45$

$0.43$

Let E = event of getting prime numbers from 1 to 100 $= {2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 49, 53, 59, 61, 71, 73, 79, 83, 89, 97}$
$∴$ $∣ n (E) = 25$
$∴$ Required probability $= \frac{25}{100} = 0.25$

Q. The probability that number selected at random from the number 1,2,3,4,5,6,7,8,...,100 is a prime, is

0.4

0.25

0.45

0.43