Let P1, P2, ......, P15 be 15 points on a circle.

Question

Let P1, P2, ......, P15 be 15 points on a circle. The number of distinct triangles formed by points Pi, Pj, Pk such that i +j + k $$\ne$$ 15, is :

Accepted Answer

Total number of triangles = ${}^{15}{C_3}$

i + j + k = 15 (Given)

Number of possible triangles using the vertices Pi, Pj, Pk such that i + j + k $$\ne$$ 15 is equal to ${}^{15}{C_3}$ - 12 = 443

Option (c)

Solutions · 1