Skip to content / Đến nội dung
ThichHocToan.com

SMO 2019 Junior Round 1 Question 21

SMO · SMO 2019 Junior Round 1

Question 21

A positive integer is said to be “twelvish” if the sum of digits in its decimal representation is equal to 12. For example, the first four twelvish integers are 39, 48, 57 and 66. What is the total number of twelvish integers between 1 and 999?