Question

In a book of 100 pages, if a page is opened at random, the probability that the number on it is a prime is

• A. $\frac{1}{2}$
• B. $\frac{1}{3}$
• C. $\frac{1}{4}$
• D. $\frac{1}{8}$

Answer 1

The correct option is C $\frac{1}{4}$

Prime numbers between 1 and 100 are: 2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 73, 79, 83, 89, 97 $=25$ cases
25 numbers out of 100 number
Probability that numbers are Prime$=\frac{25}{100}=\frac{1}{4}$