SOLUTION: 6 points are placed on the line a, 4 points are placed on the line b. How many triangles is it possible to form such that their vertices will be the given points, if a∥b?

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Question 1120837: 6 points are placed on the line a, 4 points are placed on the line b. How many triangles is it possible to form such that their vertices will be the given points, if a∥b?
i got 96 but i just wanted to check my answer

Answer by ikleyn(52814) About Me  (Show Source):
You can put this solution on YOUR website!
.
You have  6%2A%28%284%2A3%29%2F2%29 = 6*6 = 36 different triangles having one vertex in line "a" and two vertices in line "b".


Plus you have 4%2A%28%286%2A5%29%2F2%29 = 4*15 = 60 other triangles, having one vertex in the line "b" and 2 vertices in the line "a".


In all, there are 36 + 60 = 96 triangles.

Solved.