# Easy Permutation-Combination Solved QuestionAptitude Discussion

 Q. There are $7$ non-collinear points. How many triangles can be drawn by joining these points?
 ✔ A. $35$ ✖ B. $10$ ✖ C. $8$ ✖ D. $7$

Solution:
Option(A) is correct

A triangle is formed by joining any three non-collinear points in pairs.

There are $7$ non-collinear points.

The number of triangles formed,

$= {^7C_3}$

$= \dfrac{7 × (7-1) × (7-2)}{3!}$

$= \dfrac{7 × 6 × 5}{3 × 2 × 1}$

$= 7 × 5$

$= 35$