SOLUTION: The no. Of straight line obtained by joinong 16 points on a plane, no thrice of them being on the same line is

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Question 1083912: The no. Of straight line obtained by joinong 16 points on a plane, no thrice of them being on the same line is
Answer by ikleyn(52781) About Me  (Show Source):
You can put this solution on YOUR website!
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The no. Of straight highlight%28cross%28line%29%29 lines obtained by joining 16 points on a plane, no highlight%28cross%28thrice%29%29 three of them being on the same line is
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= C%5B16%5D%5E2 = %2816%2A15%29%2F%281%2A2%29 = 120. 


= the number of combinations of 16 points taken 2 at a time.


On combinations, read the lessons
    - Introduction to Combinations
    - PROOF of the formula on the number of Combinations
    - Problems on Combinations (*)
in this site.

By the way, in the lesson marked (*) you will find similar solved problem for planes in 3D . . .


Also, you have this free of charge online textbook in ALGEBRA-II in this site
    - ALGEBRA-II - YOUR ONLINE TEXTBOOK.

The referred lessons are the part of this online textbook under the topic "Combinatorics: Combinations and permutations".