There are 21 points in a plane no three of which are collinear . The number of triangle by joining them is

There are 21 points in a plane no three of which are collinear. The number of triangles formed by joining them is

There are 15 points in a plane, no three of which are collinear. Find the number oif triangles formed by joining them.

There are 15 points in a plane, no three of which are collinear. Find the number of triangles formed by joining them.

There are 20 points in plane no three of which are collinear . The number of strainght lines by joining them is

There are 10 points in a plane, out of which 6 are collinear. If N is the number of triangles formed by joining these points, then :

There are 10 points in a plane, out of these 6 are collinear. The number of triangles formed by joining these points, is

There are 10 points in a plane, out of these 6 are collinear. The number of triangles formed by joining these points, is

There are 10 points in a plane, out of these 6 are collinear. The number of triangles formed by joining these points, is

There are 10 points in a plane, out of these 6 are collinear. The number of triangles formed by joining these points, is

There are 8 points in a plane, no three of them are collinear .The number of triangles that can be formed is: