There are 14 points in a plane, out of which 4 are collinear. Find the number of triangles made by these points .
Correct Answer: 360
Explanation:
The required number of triangles = nC3 - mC3 Here, n = 14, m = 4
= 14C3 - 4C3
= (14 x 13 x 12 x 11! ) / (3! x 11!) - 4! / (3! x 1!)
= (14 x 13 x 12)/6 - 4/1
= 14 x 26 - 4
= 364 - 4
= 360
