SOLUTION: A math team of 13 people all shake hands with each other exactly once. How many hand shakes occur?
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Question 200459: A math team of 13 people all shake hands with each other exactly once. How many hand shakes occur?
Answer by solver91311(24713) (Show Source): You can put this solution on YOUR website!
The first person shakes hands with 12 different people, the second person also shakes hands with 12 different people, but one of those handshakes was counted in the 12 for the first person, so the second person actually shakes hands with 11 new people. The third person, 10 people, and so on...
So,
John

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