Out of 8 points ina plane , 5 are collinear. Find the probability that 3 points selected at random will form a triangle.

Total number of traingles-

If 2 points are selected from 5 collinear points and 1 point is selected from 3 other points, number of triangles formed =

If 1 point is selected from 5 collinear points and 2 points are selected from 3 other points, number of triangles formed =

1 triangle can be formed using 3 points after leaving 5 collinear points.

So, total number of triangles formed using 3 points =

Probability that 3 points selected at random will form a triangle

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