There are 10 points in a plane out of which 4 are collinear. Find the number of triangles formed by the points as vertices.
Choose the correct option:
A) 120 B) 116 C) 140 D) 20 E) 10
Solution: 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= 
<gadget id="calculator">120-4</gadget>
<output>116</output>
116.   Answer 116
<result>B</result>
There are 10 points in a plane out of which 4 are collinear. Find the number of triangles formed by the points as vertices.