Posted: 4/6/2016 6:32:14 PM EDT
| 87 people are in a room, and they all shake each other's hands. How many hand shakes occur? |
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I see now. It is a special case of the Pólya enumeration theorem; the number of edges of a complete platonic graph with n vertices.
(n^2-n)/2 3741 eta: The principle applies to, say, for example: the time one's brain must spend processing nonverbal cues, a, is proportional to the number of people present n, a = n(n-1)/2. |
