Three ones in a row

A fair die is rolled 55 times. What is the probability of getting at least 33 consecutive 11s somewhere in the five rolls?

Show hints (2)+
  1. Mark rolls as one (OO) / not-one (XX); count length-55 patterns with a run of 3\ge 3 OOs, weighting each XX by 55 outcomes.
  2. The favorable ordered outcomes total 9696 out of 65=77766^5=7776.

Answer

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0.0123 (± 0.0005)

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Asked at: Jane Street, Akuna Capital

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