AP EAMCET201921 Apr 2019Morning ShiftMathematicsPermutation and CombinationActual
There are 20 straight lines in a plane such that no two of them are parallel and no three of them are concurrent. If their points of intersection are joined, then the number of new line segments formed are
Options
- A3420
- B14535
- C2907
- D17955
Correct answer
B. 14535
Step-by-step solution
We know that, if there are n straight lines in a plane, no two of which are parallel and no three passes through the same point and their point of intersection are jointed then number of fresh lines thus introduced is = 1 8 n(n-1)(n-2)(n-3) aligned & = 1 8 20 (20-1) (20-2) (20-3) & = 1 8 20 19 18 17 & = 116280 8 =14535 aligned