SOLUTION: twenty points , no 3 of which are collinear, lie in a plane. Using these points, how many straight lines can be drawn

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Question 908715: twenty points , no 3 of which are collinear, lie in a plane. Using these points, how many straight lines can be drawn
Answer by richard1234(7193) About Me  (Show Source):
You can put this solution on YOUR website!
Any two points determine a unique line, since no two are collinear.

# lines = 20C2 = 20*19/2! = 190