2020 AMC 10 B
Complete problem set with solutions and individual problem pages
Steve wrote the digits , and in order repeatedly from left to right, forming a list of digits, beginning . He then erased every third digit from his list (that is, the 3rd, Gth, 9th, .. .digits from the left), then erased every fourth digit from the resulting list (that is, the 4 th, 8 th, 12 th, . . , digits from the left in what remained), and then erased every fifth digit from what remained at that point. What is the sum of the three digits that were then in the positions ?(2020 AMC 10B, Question #15)
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After erasing every third digit, the list becomes . repeated. After erasing every fourth digit from this list, the list becomes . . repeated. Finally, after erasing every fifth digit from this list, the list becomes . . repeated. Since this list repeats every digits and since are respectively in , we have that the ,, and digits are the , , and digits respectively. It follows that the answer is .
