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 Question from Izsak: What is the formula to find the number of segments that can be named by a given number of points on a line?

Hi Izsak,

A line segment is determined by two different points on the line. The segment consists of the two points and all points between them.

If you have $n$ points on the line how many ways are there to select two of them for the endpoints of a segment? How many segments are there?

Penny

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