(Q). How many distinct lines can be drawn through 10 points, 5 of which are on a straight line & remaining 5 are on other straight line which is parallel to the first straight line?
Solution:-
¹⁰C₂ – ⁵C₂ – ⁵C₂ + 1 + 1
= 45 – 10 – 10 + 2
= 27 Answer
