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Australian AMC 2019 - Senior Question 8

AMC AUSTRALIA · Australian AMC 2019 - Senior

Question 8

Consider the undulating number sequence

$1,4,7,4,1,4,7,4,1,4,\ldots,$

which repeats every four terms. The running total of the first 3 terms is 12. The running total of the first 7 terms is 28.
Which one of the following is also a running total of this sequence?
  1. 61
  2. 62
  3. 67
  4. 66
  5. 65