Jane Street–styleTraderQuant TraderQuestion #653
There are 30 people, consisting of 15 couples. Everyone shakes hands with other people, except nobody shakes hands with their own partner. You are told that 29 people each shook hands with a different number of people (for example, one person shook hands with 4 people, another with 5, etc.). How many people did the 30th person shake hands with?
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