Counting Triangles From Points

There are 5 points P1,P2,P3,P4,P5 on the side AB, excluding A and B, of a triangle ABC. Similarly there are 6 points P6,P7,...,P11 on the side BC and 7 points P12,P13,...,P18 on the side CA of the triangle. The number of triangles, that can be formed using the points P1,P2,...,P18 as vertices, is :

Ask about this question