Cuts until one orb remains
Seven orbs, labelled (attached to the ceiling) down to , hang in a vertical chain, each joined to its neighbor by a link ( links total). Each step, a uniformly random remaining link is cut, and every orb below that link falls and shatters. What is the expected number of cuts until only orb remains? Round to two decimal places.
Show hints (2)+
- Cutting link (from the top) leaves links - uniform on .
- solves to ; take .
Answer
Reveal answer →Final answer
2.45 (± 0.01)
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