Reply To: Puzzles
@Rhydwen23
We must have that both page numbers are of opposite parity (oddness/evenness) since one is a left page and one is a right page. Because of this the rightmost page must have an odd number of digits, so the smallest solution is 43/210 with 83 pages (front and back) missing. If you like your left pages even, the smallest solution is 54/321 with 133 pages missing.