Most favourite question for SSC CGL || question based on bike race or runner race track distance

In a bike race bike X beats bike y by 20 km bike Y beats bike Z by 30 km by X beats bike chat by 40 km the distance over which the race has been conduct each
runners A B and C run a race with runner a finishing 12 m i hate of runner B and 18 m ahead of Runner 3 while runner B finishes 8 M ahead of runner C each runner Travels the entire distance at a constant speed the length of Race is