Another nice puzzle, BrainTwister #3: Page turner.

Reveal solution by highlighting.

Læs mere: Puzzle 3, braintwister

For n pages:

1 <= n <= 9, n digits. 1 to 9 digits.

10 <= n <= 99, 9 + (n-9)*2 = 2n – 9 digits. 11 to 189 digits.

100 <= n <= 999, 9 + 90*2 + (n-99)*3 = 3n – 108 digits. 192 to 2889 digits.

24 pages, 9 + 15*2 = 39 digits.

183 digits, n must be between 10 and 99. 2n – 9 = 183 <=> n = 96.

636 digits, n must be between 100 and 999. 3n – 108 = 636 <=> n = 248.