Book Numbering Riddle

975.2K Views

I am compiling the Puzzlefry world almanac and it now contains lots of pages.

I know that it takes 121 digits to print the page numbers in sequence.

How many numbered pages does the book have and how many times does the number 9 appear?

Share
Add Comment

  • 1 Answer(s)

    You require 11 digits to print  first 10 pages. (1 – 9, 1 and 0 for 10) Thereafter, every page require 2 digits. Since the total number of digits used is 121, there are 110 digits remaining, which can print 55 pages of two-digit numbers. Hence, total number of pages = 65.
    The digit ‘9’ will appear on pages 9, 19, 29, 39, 49 and 59 – That’s a total of 6 times.

    Viji_Pinarayi Expert Answered on 8th May 2018.
    Add Comment
  • Your Answer

    By posting your answer, you agree to the privacy policy and terms of service.
  • More puzzles to try-