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. $0.43$

Answer 1

Answer: (B)

$0.25$

Answer 2

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