There are 10 points in a plane out of which 4 are collinear. Find the number of triangles formed by the points as vertices.

Explanation:-

The number of triangle can be formed by 10 points = ¹⁰C₃.
Similarly, the number of triangle can be formed by 4 points when no one is collinear=⁴C₃.
In the question, given 4 points are collinear, Thus, required number of triangle can be formed,
= ¹⁰C₃-⁴C₃ = 120-4 = 116.