Question

A book has pages numbered from 1 to 100. If a page is chosen at random, what is the probability that the sum of the digits on the page is 9?

• A. 6/85
• B. 7/85
• C. 9/85
• D. 8/85

Answer 1

The correct option is C

9/85

Given,

Total number of pages in the book = 100

The required page numbers such that the sum of the digits on the page is 9 will be 09, 18, 27, 36, 45, 54, 63, 72, 81, 90

That makes 10 favourable outcomes out of 100.

Thus, the required probability = $\frac{\text{number of favourable outcomes}}{\text{total number of outcomes}}=\frac{10}{100}=\frac{1}{10}$ .