Skip to content / Đến nội dung
ThichHocToan.com

BEBRAS 2026 Grade 9-10 Round 2 Ext Question 2

BEBRAS · BEBRAS 2026 Grade 9-10 Round 2 Ext

Question 2

George encodes a word in two steps. First read left to right and concatenate the letters in odd-numbered positions: bread gives bed. Then read right to left and append the remaining letters: bread becomes bedar. Repeating the procedure eventually restores the original word. For example milk→mlki→mkil→milk takes three encodings. How many encodings first restore society?
  1. 6
  2. 4
  3. 7
  4. 5