There are two parallel lines. First line has two points  A & B while second line has 10 points. How many triangle can be formed taking these 12 points as vertices of triangle

(Q). There are two parallel lines. First line has two points  A & B while second line has 10 points. How many triangle can be formed taking these 12 points as vertices of triangle?
Solution:-
Required number of triangles
= ¹²C₃ – ¹⁰C₃
= 220 – 120
= 100         Answer