Out of thirty points in a plane, eight of them are collinear. The number of straight lines that can be formed by joining these points, is

Step-by-step solution

Total number of points in a plane is 30 . Out of them, 8 points are collinear. Total number of straight lines formed aligned & = ³⁰ C₂- ^8 C₂+1 & = 30 29 2 - 8 7 2 1 +1 & =435-28+1=408 aligned