(Q). Consider ‘n’ straight lines in a plane such that no two of which are parallel and no three of which pass through the same point. How many new straight lines can be drawn from the point of intersection of these straight lines?
Solution:-
Since each line is intersected by every other line at a point.
So number of intersection point = number of ways to select 2 straight lines out of ‘n’ lines
= ⁿC₂
∴ Number of straight line from x points is
= ˣC₂
Since in the question we are asked only th new lines & we can not here one thing that on particular line is interesected by remaining (n-1) straight lines a (n-1) points & from these points we will not get a new line. Hence from one line we will not get ⁿ⁻¹C₂ lines.