Skip to content / Đến nội dung
ThichHocToan.com

VTMO 2026 - Grade 9 - Semifinal - SET 05 - Self-study Question 22

VTMO · VTMO 2026 - Grade 9 - Semifinal - SET 05 - Self-study

Question 22

A number is called a diamond number if rotating the paper on which it is written by180 degrees leaves the same number. The allowed examples include69,88,96,0,8;25,52,11 are excluded because the property fails in some writing styles. How many six-digit diamond numbers are there?
  1. 45
  2. 52
  3. 48
  4. 50
  5. 65