Hello friends can someone tell me how to approach these problems? I participated in this practice round 1 and could not solve these problems. Can someone tell me the approach to solve these problems. Thanks in advance. @vijju123 @taran_1407 @vivek_1998299 @meooow @john_smith_3 @aryanc403 @vbt_95 Contest is over so we can have a discussion over the approach used or can be used. asked 14 Jul '18, 12:37

The A problem is mostly number of ways of choosing 3 lines such that no two of them have a same angle,since n is small u can iterate over all triplets.
As any 2 line which are not parallel will intersect a some point,so for 3 lines,line (1,2) intersects at A,line(2,3) at B,line(1,3) at C,and since it is said that they are concurrent A!=B!=C