If-7-points-out-of-12-are-in-the-same-straight-line-then-the-number-of-triangles-formed-is-

Question Number 81725 by zainal tanjung last updated on 14/Feb/20

If 7 points out of 12 are in the same

straight line, then the number of

triangles formed is

Commented by Tony Lin last updated on 14/Feb/20

C_{3}^{5} + C_{2}^{5} C_{1}^{7} + C_{1}^{5} C_{2}^{7} = 185