Question

There are $10$ points in a plane.Of these ten points four points are in a straight line and with the exception of these four points no other three points are in the same straight line. Find the number of straight lines formed.

• A. $35$
• B. $40$
• C. $30$
• D. $25$

Answer 1

Answer: (B)

$40$

$10$ Points $⟶4$ are in straight line

For a straight line

Two end points are neded

${\Rightarrow }^{10}{C}_2{-}^4{C}_2+1=45-6+1=40$