Skip to content / Đến nội dung
ThichHocToan.com

1997 AMC 12 Question 24

AMC12 · 1997 AMC 12

Question 24

A *rising number*, such as $34689,$ is a positive integer each digit of which is larger than each of the digits to its left. There are $\binom95=126$ five-digit rising numbers. When these numbers are arranged from smallest to largest, the $97$th number in the list does not contain the digit
  1. $4$
  2. $5$
  3. $6$
  4. $7$
  5. $8$