Skip to content / Đến nội dung
ThichHocToan.com

AMO 2027 Grades 9-11 SET 1 - Self-study Question 4

AMO · AMO 2027 Grades 9-11 SET 1 - Self-study

Question 4

What is the total number of different ways that the blanks below can be filled in so that the resulting four-digit number is a multiple of 11? $$9\ \square\ 5\ \square.$$ Each blank holds one digit; the two digits need not be different.

Choose one option.
  1. 9
  2. 10
  3. 18
  4. 11
  5. 8