The number of digits you have to type to write all the page numbers of a book starting from 1 (first page) is 2019. What is the number of pages in that book?

The number of digits you have to type to write all the page numbers of a book starting from 1 (first page) is 2019. What is the number of pages in that book?

Answer: 709

Explanation:

From 1 to 9 = 1 digit x 9 = 9 digits

From 10 - 99 = 2 digits x 90 numbers = 180 digits

From 100 - 699 = 3 digits x 600 numbers = 1800 digits

From 700 - 709 = 3 digits x 10 numbers = 30 digits

Total = 9 + 180 + 1800 + 30 = 2019 digits