Out of 10 given point, 3 are collinear. How many different straight line can be drawn by joining any 2 points from those 10 points?

Step-by-step solution

If there are m points in which n points are collinear (m n) then number of different straight line are ^m C₂- ^n C₂+1 ¹⁰ C₂- ^3 C₂+1= 10 9 2 -3+1=45-3+1=43