Two lines intersect at O. Points $A_1,A_2,........A_n$ are taken on one of them and $B_1,B_2,........B_n$ on other. The no. of triangles that can be drawn from with the help of these 2n points and point 'O' is ? - Clay6.com, a Free resource for your JEE, AIPMT and Board Exam preparation

Two lines intersect at O. Points $A_1,A_2,........A_n$ are taken on one of them and $B_1,B_2,........B_n$ on other. The no. of triangles that can be drawn from with the help of these 2n points and point 'O' is ?