I have 2 very challenging secondary 1 questions here.

1. A leaf was torn out from a book. The page numbers on the remaining pages of the book summed up to 1000. How many pages were there in this book at first? Which pages were torn out?[ans: 45 pages, 17 & 18 torn out]

2. Given that a, b, and c are non-zero digits and satisfy acb+bac+bca+cab+cba=3194

[ans: 358, hint given: consider S=abc+acb+bac+bca+cab+cba=222(a+b+c)]

Anyone can help? Many Thanks!