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AMO 2027 Grades 8-9 SET 4 - Self-study Question 11

AMO · AMO 2027 Grades 8-9 SET 4 - Self-study

Question 11

Tom writes all the natural numbers not exceeding 2021 whose digits are all even in ascending order: $2,4,6,8,20,22,24,26,28,\ldots$. How many numbers in total does Tom write?