Quant Permutation and Combinatiopn

There are 10 Points on a one straight line and 11 points on another straight lines... How many different types of triangles can be formed using these points as a vertices ??

 

sol>Here 2 Cases possible

1)take 1 point from the line which contain 10 points, and now we have to select 2 points from the other line so

2) take 1 point from the line which contain 11 points and now we have to select 2 points from the other line so

Case 1:

11C2 = 55

now 10 such possibilities so 55 X 10 = 550

case 2:
10C2 = 45

now 11 such possibilities so 45 X 11 = 495

hence total = 550 + 495 = 1045

is the ans