Q5.If 10 lines are drawn in a plane such that no two of them are parallel and no three are concurrent, then the total number of points of intersection are
Q6.A number x is chosen at random from the first 100 natural numbers. Let A be the event of numbers which satisfies [(x − 10)(x − 50)] / [x − 30 ] ≥ 0 , then P ( A) is