Formula for lines that can be drawn using $n$ points

Please help me! How many lines can be drawn using $6$ points? Each line is made by connecting $2$ points.

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You need to know more about the points in order to answer this question precisely. For example all 6 points could be on the same line and so you can only make one line with the 6 points. – Wintermute May 12 '13 at 13:28
What have you tried? (How many pairs of points do you have? How many lines can you draw at most between each pair of points?) – TMM May 12 '13 at 13:28