The lines L 1 , L 2 , . .. , L 20 are distinct. For n = 1 , 2 , 3 , . .. , 10 all the lines L 2 n − 1 are…

The lines L1,L2,...,L20 are distinct. For n=1,2,3,...,10 all the lines L2n1 are parallel to each other and all the lines L2n pass through a given point P. The maximum number of points of intersection of pairs of lines from the set L1,L2,...,L20 is equal to:

Solution

Given:

Out of 20 numbered lines, even numbered lines are concurrent, odd number lines are parallel.

So, the maximum number of intersection points will be given by,

N=1point of intersection when both lines are even+0point of intersection when both lines are parallel+C110×C110point of intersection when 1 odd and 1 even line meets

N=1+0+100

N=101

Asked in: JEE Main 2024 (01 Feb Shift 2)

Practice more Permutation Combination questions on Aicharya