There are several red and several white boxes on the table, each of these boxes contains at
least one ball. A positive integer number not exceeding 1111 is written on each of these balls.
- Any two boxes contain different number of balls.
- No box contains two balls with the same number.
- For each 1 ≤ i ≤ 1111 there is at most one red box containing ball with number i.
- For each 1 ≤ i ≤ 1111 there is at most one white box containing ball with number i.
Find the maximal possible number of boxes on the table.
Correct Solutions by,
- Toshihiro Shimizu Kawasaki, Japan
- Roger Bengtsson Lund, Sweden
- Magnus Jakobsson Lund, Sweden
- Arda Karahan Trabzon Fen Lisesi
- Vedat Deveci İstanbul
- Abdulkadir Tanrıverdi Eskişehir
- Yusuf Büyük Haliç University
- Özer Aydemir
- Partrik Wild Lund, Sweden
- K. Sengupta Calcutta, India
- Tuna Demircioğlu
- Ananda Raidu Bangalore, India
- Mümtaz Ulaş Keskin Erciyes University
Solution: http://www.fen.bilkent.edu.tr/~cvmath/Problem/2312a.pdf